Udaykrishna–Sibi K. Thomas

Both Siby and Udayakrishna started their career as assistant directors. Siby assisted Balu Kiriyath and Sandhya Mohan, while Udayakrishna assisted screenwriter A.R.Mukesha and was assistant director under Balu Kiriyath, Ali Akbar, K. Madhu and Venu B. Nair.[5] Manoj K. Jayan prodded them into a partnership and agreed to star in their directorial debut.[5] However, that project did not work out. Subsequently, they wrote their first script, Hitler Brothers (1997), for Sandhya Mohan, followed by Mayajalam for Balu Kiriyath. Both films failed at the box office.[5] The duo's first hit came through Mattuppetti Machan directed by Jose Thomas, followed by Udayapuram Sulthan.[5] Then came Sundrapurushan, which was a moderate success. It was followed by Rajasenan's successful movies, Darling Darling and Malayalimamanu Vanakkam. C.I.D. Moosa, was a notable success. They associated with Johny Antony in most of his directorial ventures thereafter, including the commercially successful Kochi Rajavu and Thuruppu Gulan.

They worked with veteran director Joshiy in Runway, Lion and July 4, and in the landmark Malayalam film Twenty:20. Twenty:20 was produced by Association of Malayalam Movie Artists in association with Dileep's Grand Productions and starred most major actors of Malayalam cinema. The film became the highest grossing Malayalam film of all time and brought appreciations for Siby and Udayakrishna.[6] Twenty:20 was followed by Ee Pattanathil Bhootham, which was panned by the critics and an average grosser. In 2010, they made a comeback with Pokkiri Raja, which went on to become a big success and the highest-grossing film of the year.[7] However, critical responses for Pokkiri Raja were mostly mixed. They scripted debutante Thomson K. Thomas's Kaaryasthan. Despite negative reviews from critics, the film closely followed Pokkiri Raja in collection records of the year.[7] Their only film in 2011 was Christian Brothers with Joshiy, which became a success.[8][9] They scripted two films in 2012, Mayamohini and Mr. Marumakan. The former was a success and was among the highest-grossing films of the year while the latter, despite heavy criticism, became an average hit. The last release in their combination is Ivan Mariyadaraman.

They are known for heavy usage of slapstick comedy. The protagonists often hail from rich Christian and Hindu families and often the film revolves around family ties or the rivalries between two families.[10]

The duo are often criticised for the lack of content in their screenplays and for the continuous association with superstars. They explain:

Our mantra is to make sure that those who have invested money in the film gets maximum returns and those who pay for the ticket get entertained. We are limiting our experiments to the stars and their stardom as of now.[5]

• Udayakrishna at IMDb
• Siby K. Thomas at IMDb
• "Interview: Udayakrishna-Siby K. Thomas". Varnachithram.
• "Video interview: Udayakrishna-Siby K. Thomas". Indiaglitz. 14 April 2007.