Leaf-litter geckos of the genus Sphaerodactylus are highly diversified but their small size and secretive habits have made them difficult to study. In 1972–1973, we conducted a demographic study on a population of S. vincenti ronaldi from a xerophytic forest in Martinique, with the prediction that seasonality in local climatic conditions, especially precipitation, should cyclically constrain food consumption, growth, and reproduction. We used a mark–recapture method to get basic data on population structure and density. We sacrificed 62 specimens to determine diet and reproductive conditions. Individual age, growth, and longevity were assessed by skeletochronology. Lizards were ubiquitous in the 900 m² study area, with most found singly under humid rotten logs. Population density averaged 8220 geckos/ha. Individual movements were very limited over a six-month period. We noted a high incidence (62%) of tail autotomy. Diet included a diversity of small invertebrate prey (15 different orders) with collembolans being most abundant. However, food consumption (measured as stomach content and intestine masses) dropped to a minimum in late dry season, a cyclic pattern most likely responsible for the observed lines of arrested growth (LAGs) registered in the femoral bone cortex of these lizards. Sequences of LAG dimension and modal distributions of snout–vent lengths (SVL range: 13–32 mm) revealed a slow growth rate (0.66 mm/month) during the first year of life with both genders attaining sexual maturity at 25–26 mm SVL and 18–20 months of age. Longevity did not exceed 48 months. Reproduction appeared seasonal, with the geckos laying eggs at an undetermined frequency during a period lasting approximately seven months. Egg size and incubation time were similar to other Sphaerodactylus of comparable body size. These results indicate special constraints associated with body size in species of Sphaerodactylus living in xerophytic habitats. However, for S. vincenti, a species that extends its range to other mesic/humid habitats in Martinique and three other nearby island banks, it is not known if larger subspecies (up to 40 mm SVL) suffers the same constraints in food intake, growth, and reproduction as observed in this study for S. v. ronaldi.