The reproductive cycle of the tropidurid lizard, Eurolophosaurus nanuzae, was studied at the montane habitat of Serra do Cipó, Minas Gerais State, Brazil, from June 1996 to June 1997. Reproductive activity of E. nanuzae was cyclic, occurring from the middle of the dry season to the end of the wet season. Female reproductive activity was influenced by photoperiod and by long term precipitation and temperature. Males exhibited sperm in their testes throughout the year, and their reproductive activity was not related with any of the climatic factors analyzed. Fat storage varied inversely with reproductive activity and was more accentuated in females. Mean clutch size was 2.06 (±0.36 eggs) and was not related to female body size. The effects of precipitation on the reproductive cycle of E. nanuzae could be related to the microclimatic conditions necessary for embryo development and hatchling survivorship, as well as to the greater food availability for hatchlings during the wet season.