The oleoresin of the copaiba tree (Copaifera sp., Fabaceae) is traditionally used in Brazilian herbal medicine to treat a variety of illnesses and symptoms. This study, conducted according to the OECD Guideline 414, provides data on the developmental toxicity of oleoresin from C. reticulata (COPA-R) in rats. Pregnant Wistar rats (25 per dose group) were treated by gavage with COPA-R (0, 500, 1000 and 1250 mg/kg bw/day) on gestation days (GD) 6-19 and Caesarean sections performed on GD20. Implantations, living and dead fetuses and resorptions were recorded. Half of the fetuses from each litter were examined for visceral abnormalities and the remaining were cleared and stained for skeleton evaluation. COPA-R was maternally toxic (reduced food intake and weight gain) and embryotoxic (lower fetal body weight and increased occurrence of fetal skeleton variations) at the two highest doses, but did not cause embryo deaths or fetal malformations at any dose level. The study derived an oral no-observed-adverse-effect-level (NOAEL) for maternal and developmental toxicity induced by COPA-R of 500 mg/kg bw/day. The results suggest that copaiba oleoresin does not pose a health risk to pregnant women when used according to the recommended doses (up to five drops, three times a day).