Thaniyavarthanam (English: The Repeating Rhythm) is a 1987 Malayalam drama film written by A. K. Lohithadas and directed by Sibi Malayil. It stars Mammootty as school teacher Balagopalan, Thilakan as the uncle of the matrilineal family, Mukesh as Gopinathan, and Kaviyoor Ponnamma. The film became a cult classic. Thilakan won Kerala State Film Award for Second Best Actor.

Upon release, it received critical acclaim. The film discusses a variety of topics, such as superstition and orthodoxy in rural Kerala, attitudes towards mental illness, the difference in attitude between people of different generations, and the decline of once-proud Nair "joint families". It was actor Thilakan who recommended Mammootty for the lead role (Balagopalan). The screenplay by Lohithadas stands out even today because of its scientific accuracy and realistic depiction.