The frequency distribution of various consanguineous marriages was studied in the city of Madras, Tamil Nadu, South India. Parallel first cousin marriages (PFC) were found to occur in appreciable frequencies in all caste groups of Hindus. While it has been generally believed that PFC marriages among Hindus are mere exceptions and are usually not tolerated, our data show that they can no longer be treated as exceptions. The high frequency (27 per cent) of PFC marriages in some Hindu communities necessitates in-depth studies to elucidate the forces at work which go against the very fundamentals of Dravidian kinship.