Although a highly visible component of the West Indian herpetofauna, few data address the biology of Curly-Tailed Lizards (Leiocephalus). We examined sexual dimorphism in size and head shape and reproductive life-history characteristics for five species of Leiocephalus from the Dominican Republic. Many hypotheses have been posited to explain head shape dimorphism in lizards. Previous studies on Leiocephalus lizards failed to support the niche divergence hypothesis. Consequently, we examined patterns of head shape dimorphism by measuring the scaling relationships of head dimensions of males and females for each species. Head dimensions of the sexes mostly scaled isometrically or with negative allometry, which may support the differential growth hypothesis, although patterns in one species (Leiocephalus semilineatus) suggest that sexual selection may be operative. Clutch sizes varied from 1–4 eggs across species, but mean clutch size generally does not differ significantly among species. Similarly, egg size varies little across species, with only the smallest of the species examined, L. semilineatus, differing significantly from the other species. Therefore, although maximum female snout-vent lengths differ by as much as 50 mm, reproductive characteristics are relatively static. These data are suggestive of an optimal reproductive strategy for Leiocephalus lizards, although detailed experimental data are necessary to examine this fully.