Field observations and mark–recapture sampling carried out in the Reserva Ducke in Central Amazonia provided information on the occurrence of reproductive events of the Brilliant-Thighed Frog, Allobates femoralis, in the context of seasonal rainfall. In addition, we report on the daily pattern of calling activity and the use of space by marked individuals. Rainfall was a strong determinant of the calling and breeding activities at a seasonal scale. The phenology of A. femoralis was affected by interannual differences in both the length and severity of the dry season. This species showed a consistent diel pattern throughout the year, with calling activity peaking between 1500 and 1600 h. At the seasonal scale, calling activity was higher during the wet months and was correlated positively with monthly rainfall. Although recruitment is concentrated in the late wet season, our observations of juveniles in the smallest size classes throughout the year indicated that reproduction occurs sporadically even during the dry season, probably stimulated by isolated episodes of rainfall. Territories varied greatly in size, ranging from 4.8 to 175.7 m². Females did not establish or defend territories. Individuals of both sexes showed regional interseasonal attachment, and males maintained territories for up to 255 days.