Chrysemys dorbigni is a common diurnal turtle in the Taim Ecological Station. Though females may choose nesting sites in the same area they do it isolately, not in groups. Data on female nesting site selection, building of nest and egg laying are given. Under laboratory and field conditions development was followed from the egg stage to the emergence of hatchlings and growth of juveniles. One to 16 eggs are laid per clutch. Nesting activity is coincident with periods of higher temperatures in the field. Abiotic conditions and incidence of predation have been considered to estimate the success of clutches.