From 1986–87 Syal presented Sunday East, a BBC programme.

Syal is an occasional singer, having achieved a number one record with Gareth Gates and her co-stars from The Kumars at No. 42 with Spirit in the Sky, the Comic Relief single. She earlier (1988) provided vocals for a bhangra version of "Then He Kissed Me" – composed by Biddu and with the Pakistani pop star Nazia Hassan – as part of the short-lived girl band Saffron. In June 2003 she appeared as a guest on BBC Radio 4's Desert Island Discs programme with a selection of music by Nitin Sawhney, Madan Bala Sindhu, Joni Mitchell, Pizzicato Five, Sukhwinder Singh, Louis Armstrong and others. The luxury she chose to ease her life as a castaway was a piano.

Syal wrote the screenplay for the 1993 film Bhaji on the Beach, directed by Gurinder Chadha, of Bend It Like Beckham fame. She was on the team that wrote and performed in the BBC comedy Sketch show Goodness Gracious Me (1996–2001), originally on radio and then on television. She was a scriptwriter on A.R. Rahman and Andrew Lloyd Webber's Bombay Dreams and she played the grandmother Sushila in the International Emmy-award-winning series The Kumars at No. 42, which ran for seven series.

She was appointed Member of the Order of the British Empire (MBE) in the 1997 New Year Honours and in 2003 was listed in The Observer as one of the 50 funniest acts in British comedy. She was appointed Commander of the Order of the British Empire (CBE) in the 2015 New Year Honours for services to drama and literature.

Syal won the National Student Drama Award for performing in One of Us which was written by Jacqueline Shapiro while at university. She won the Betty Trask Award for her first book Anita and Me and the Media Personality of the Year award at the Commission for Racial Equality's annual Race in the Media awards in 2000. She was given the Nazia Hassan Foundation award in 2003.

In 2004, she took part in one episode of the BBC series Who Do You Think You Are?, which investigated her family history. Syal discovered that both her grandfathers had campaigned against British rule and presence in India: one as a communist Journalist, the other as a Punjab protester who was imprisoned and tortured in the Golden Temple.

In January 2005, Syal married her frequent collaborator, Sanjeev Bhaskar, who plays her grandson in The Kumars at No. 42; the marriage ceremony took place in Lichfield, Staffordshire. They have a son, born 2005. Syal has a daughter from her previous marriage to Journalist Shekhar Bhatia. Her brother is investigative Journalist Rajeev Syal.

In October 2008, she starred in the BBC Two sitcom Beautiful People. This role, as Aunty Hayley, continued in 2009. Syal starred in the eleventh series of Holby City as consultant Tara Sodi. In 2009, she guest starred in Minder and starred in the film Mad, Sad & Bad. In 2010, she played Shirley Valentine in a one-woman show at the Menier Chocolate Factory, later transferring to Trafalgar Studios. In the same year she played Nasreen Chroudhry in two episodes of Doctor Who alongside Matt Smith.

In February 2009, Syal was one of a number of British entertainers who signed an open letter printed in The Times protesting against the persecution of Bahá'ís in Iran.

In January 2011, Syal took part in the BBC Radio 4 programme My Teenage Diary, discussing growing up as the only British Asian girl in a small English town, feeling overweight and unattractive.

Having studied English at university and penned two novels and a variety of scripts and screenplays, Syal was chosen as one of the guests on "The Cultural Exchange" slot of Front Row on 30 April 2013, when she nominated To Kill a Mockingbird by Harper Lee as a piece of art work which she loved.

She received her CBE from the Prince of Wales on 6 May 2015 at Buckingham Palace.

In 2017, Syal was elected a Fellow of the Royal Society of Literature.