Established actress (1996–2000)
In 1996, Kapoor appeared in 10 films. Five of them — Papi Gudia, Megha, Bal Bramhachari, Sapoot and Rakshak — were commercially unsuccessful. Her next release was David Dhawan's romantic comedy Saajan Chale Sasural, co-starring Govinda and Tabu. Saajan Chale Sasural emerged as a commercial success. For her fifth release, Kapoor was paired opposite Suneil Shetty in S. Deepak's box office hit Krishna. She starred alongside Sunny Deol, Salman Khan and Tabu in Raj Kanwar's romantic drama Jeet. She played Kajal, a woman who falls in love with a criminal, but ends up marrying another man. Finishing up as the second highest-grossing film of the year, Jeet emerged as a "super-hit" at the box office. Critical reaction was positive on both the film as well as Kapoor's performance.
That same year, Kapoor starred in Dharmesh Darshan's romantic drama Raja Hindustani opposite Aamir Khan, in which she played a rich, beautiful heiress who falls for a lowly guide and driver. A modern-day remake of Jab Jab Phool Khile (1965), the film emerged as the highest-grossing film of the year and won Kapoor her first Filmfare Award for Best Actress. Reviewing her performance for India Today, Anupama Chopra described Kapoor as a "revelation" and "the lifeblood of this otherwise banal film." The film's success established Kapoor as a leading actress of Hindi cinema, and marked a significant turning point in her career. Raja Hindustani was not only the biggest commercial success of 1996, but also one of the most successful films of all time in India with worldwide revenues of ₹765 million (US$7.9 million). Kapoor's final release of 1996 was Suneel Darshan's action film Ajay, with Sunny Deol. The film was also a financial success.
In 1997, Kapoor re-united with David Dhawan for two projects, the comedy film Judwaa (alongside Salman Khan and Rambha), and the romantic comedy Hero No. 1 (opposite Govinda). The former's concept was similar to Gopi Kishan – it tells the story of twin brothers who are separated at birth and re-unite in their youth. Kapoor and Rambha played the love interests of Khan's characters. In Hero No. 1, she played Meena Nath, a girl who falls in love with Govinda's character despite facing disapproval from her strict grandfather (played by Paresh Rawal). Both films were critically and commercially successful, and Kapoor gained praise for her comedic timing. She eventually received a nomination for the Zee Cine Award for Best Actress for Hero No. 1. She next starred in the Mehul Kumar-directed dramas Lahu Ke Do Rang and Mrityudata, both of which were critical and commercial failures.
Kapoor's fifth and final release of 1997 was Yash Chopra's musical romantic drama Dil To Pagal Hai. Co-starring Shah Rukh Khan, Madhuri Dixit and Akshay Kumar, the film depicts the love lives of the cast and crew in a musical dance troupe. Kapoor played Nisha, a bubbly dancer who secretly falls in love with her best friend (played by Khan), who unites with the girl he loves (played by Dixit). Initially hesitant to take on the supporting role, Kapoor was cast by Chopra (who was impressed by her work in Raja Hindustani) after several leading actresses of the time had rejected it. Dil To Pagal Hai emerged as a blockbuster at the box office and proved to be the highest-grossing film of the year. Kapoor received widespread praise for her portrayal, and she eventually won the National Film Award and Filmfare Award for Best Supporting Actress.
Kapoor's diminutive comeback in 1999 proved to be good as she took part in the year's most successful films. Kapoor starred in four hits. She next re-united with Dhawan and Salman Khan (alongside Sushmita Sen) for the romantic comedy Biwi No.1, in which she portrayed Pooja, a woman whose husband gets involved in an extra-marital affair with a model. The film, which emerged as a major commercial success, earned Kapoor critical praise for her performance. Kapoor received a second Best Actress nomination at Filmfare for her work in the film. She proved to be successful with comedy films, as another of David Dhawan's films Haseena Maan Jaayegi, did fairly well at the box office. Kapoor collaborated for the first time with the Rajshri Productions for the family drama Hum Saath-Saath Hain: We Stand United, opposite Saif Ali Khan. The film featured an ensemble cast (Mohnish Behl, Salman Khan, Sonali Bendre and Tabu), proving to be one of the biggest Hindi film successes of all time in the market, earning ₹817 million (US$8.5 million) worldwide. Alok Kumar stated, "Karisma doesn't have much to do, but looks good in doing whatever she does." Her last release of the year, Jaanwar, opposite Akshay Kumar, was another box office hit, making her the most successful actress of the year. Silsila Hai Pyar Ka was her other film of the year.
Kapoor's first release of 2000 was Dhawan's romantic comedy Dulhan Hum Le Jayenge, opposite Salman Khan. She played Sapna, a girl who falls for Khan's character while on a foreign trip, however, she finds it tough to convince her three uncles of this relationship. The film finished up as one of the biggest hits of the year. Aparajita Saha of Rediff commented: "Karisma Kapoor and Salman Khan elicit more than their fair share of cat-calls in the movie and make a delectable pair. Both are in form – Karisma kapoor looks glamorous and at ease while Salman khan has perfected the lost-boy-muscle-man get-up". Kapoor's next two releases, the romantic comedies Chal Mere Bhai (opposite Khan and Dutt) and Hum To Mohabbat Karega (opposite Bobby Deol) failed to do well at the box office.
That same year, Kapoor won her second Filmfare Award for Best Actress, for portraying the title role of a disillusioned girl in search of her brother, in Khalid Mohammed's acclaimed crime drama Fiza. Cast against type in a non-glamorous role, her performance was highly applauded, several critics noted her for showing great emotional range and depth. Mimmy Jain of The Indian Express, in a positive review, wrote: "As the young girl who is sick of the suspense and disruption that her brother's disappearance has caused in her family's life, as the obstinate daughter who will not listen to her mother's plea to let her keep hoping for her son, as the determined sister who keeps on in her hunt for her brother despite all odds and then seeks to keep him on the right path, this is a new Karisma, and one that delivers a superbly flawless performance." The film emerged as a "semi-hit" at the box office with a worldwide gross of ₹878 million (US$9.1 million).
