This paper deals with the process of mating among captive aye-ayes (Daubentonia madagascariensis). Data on sexual behaviour of 3 wild-caught aye-ayes were collected over a period of 3 years (1986-1989). The group of 2 adult females and a young male was housed at the Vincennes Zoo, Paris. The seasonal poly-oestrous sexual cycle was found to be marked by four clear phases of the females’ vulval tumescence and coincided with sexual interest shown by both sexes. The external genitalia of the females are described, as are marking behaviour and sexual behaviour patterns before, during and after copulation. The behaviour and sexual cycles of these 2 females were compared with records from other lemur