Boids occur in North, Central and South America, the West Indies, Africa, including Madagascar, Asia and in some Pacific Islands as well. In Brazil they occur in a wide range of habitats and climatic zones throughout the country. This study presents reproductive and morphometric data for eleven Brazilian boid species and subspecies (Boa c. contrictor, B. c. amarali, Corallus caninus, Co. hortulanus, Co. cropanii, Epicrates c. cenchria, Ep c. assisi, Ep c. crassus, Eunectes murinus, Eu. deschauenseei and Eu. notaeus) including some morphometric data for Madagascan (Sanzia madagascariensis and Acrantophis dumerili) and Pacific boas (Candoia carinata, Ca. aspera and Ca. bibroni). These large snakes present a very conservative pattern in terms of seasonality in female reproductive cycles, size at maturity, litter and offspring relative size, and reproductive frequency. The reproductive pattern is similar among the boid species we studied and also similar to pythonids. Females' cycles are non-annual and always seasonal, usually with births occurring mostly in the spring-summer. These snakes show sexual dimorphism occurs in mean body length, head size, spur size and stoutness. In species in which males exhibit combat behavior prior to the mating season, mean body size dimorphism is not present (i.e. Ep. cenchria subspecies). Boid males' reproductive cycles are more variable, being continuous or seasonal depending on the species.