Best-remembered as Jaspreet Kapoor aka Sweetu from the film Kal Ho Naa Ho starring Shahrukh Khan and Priti Zinta, Delnaz Irani made her debut acting debut in Bollywood films C.I.D (1999). Mostly seen in comic roles, the actress has worked alongside superstars of the Bollywood, including Amitabh Bachan, Juhi Chawla, Saif Ali Khan, Akshay Kumar, Bipasha Basu, Shahid Kapoor and Kareena Kapoor. Her Bollywood film credits are Dil Ne Jise Apna Kaha (2003), Humko Deewana Kar Gaye (2006), Bhootnath (2008) and Kyaa Super Kool Hai Hum (2012) being her last appearance on the silver screen. After six years away, Irani made a come back in Gujarati film Aavuj Reshe (2018).

While away from the film industry, she has appeared in various TV serials like Ek Mahal Ho Sapno Ka (1999-2002), Sanya (2005-2006), Son Pari (2005), and Jamai Raja (2014-2016). She has also participated in television reality shows such as Nach Baliye (2007), Zara Nachke Dikha (2008), Bigg Boss 6 (2012), Comedy Circus (2013), and Power Couple (2015).