The lemurs of Madagascar typically exhibit a strictly seasonal pattern of breeding, with a limited number of successive estrous cycles occurring at a particular time of the year, which varies from species to species. Previous reports indicated that aye-ayes also exhibit such a strictly seasonal polyestrous pattern. Data from the author’s 2-year field study of aye-ayes on the island of Nosy Mangabe, combined with information from recently initiated captive breeding programs, now indicate that this species in fact shows an extended breeding season or even year-round breeding. Actual mating or signs of estrus were observed in the field throughout a 5-month period (October–February). Further, data from captured pregnant females and young offspring indicate that births take place during the period from February to September. Apart from aye-ayes, extended breeding periods have been reported for wild Eulemur coronatus and for captive Eulemur fulvus and Mirza coquereli. Analysis of information on seasonal variation in food availability for aye-ayes and other lemurs provides no clear evidence that the degree of seasonality of breeding is directly dependent on ecological factors.