Abstract: Community structure, microhabitat use, sex ratio and sexual dimorphism were investigated in the lizard, Agama agama spinosa from the north western coast of Egypt. This species is a rock-dwelling and occupy different, but overlapping crevices of rocks and old buildings. All individuals prefer the horizontal crevices on which they can perch in close proximity to the crevices. The proportion of males in the adult sample is 45%. Irrespective of sex, there were 60.2% adults and 39.8% juveniles in the total sample. Generally, the group size ranged from five to eight individuals sharing the same crevice included one adult male at least. Males apparently reach larger body sizes than females and also have larger heads and longer tails. The observed dimorphism in body and head sizes may therefore not necessarily be the result of sexual selection, but could be the result of differential energy allocation by females.