The study of space use may help us investigate the reproductive strategies being used by males and females of a particular species. In a two-year study, home range sizes were recorded in the lizard Liolaemus quilmes, comparing males and females (n = 52 for each sex), by season and by year. Males had significantly larger annual home ranges than females. They also showed greater variability in home range sizes from one year to another, particularly during the reproductive season. When home range size in males was correlated to the number of females within those areas, during the reproductive season, significantly more females were found in larger-sized home ranges, whereas no significant correlation was found during the post-reproductive season, when home ranges of males were smaller. When home range size of males was correlated to their snout-vent lengths and weights, no significant correlation was found. Males that occupied smaller areas and overlapped with fewer females, may suggest a mate-guarding type strategy, tending toward monogamy. Males that occupied larger areas, overlapping with more females, may be tending toward a polygynous strategy. Female home ranges, on the other hand, remained stable throughout the study except for a tendency to be larger during the post-reproductive than during the reproductive season. This suggests that food availability during their post-oviposition recovery period could be more important than number of males.