AIM: To evaluate the morphological aspects of coronal dentinogenesis in the first molars of 1- and 5-day-old rats whose mothers were treated with fluoxetine hydrochloride during pregnancy. METHODS: Twelve pregnant Wistar rats were divided randomly into three groups: group C (control), group FL (fluoxetine administered at 10 mg/kg bodyweight), and group FX (fluoxetine administered at 20 mg/kg bodyweight). Saline (0.9%) solution or fluoxetine hydrochloride was administered subcutaneously for the first 21 days of pregnancy. Subsequently, the offspring of these animals was subdivided into subgroups according to age of tooth germ development to be studied: 1 and 5 days of life. C1 and C5 (control group 1 and 5 days of age); FL1 and FL5 (groups treated with 10 mg/kg fluoxetine at 1 and 5 days of age); FX5 and FX1 (groups treated with 20 mg/ kg fluoxetine at 1 and 5 days of age). RESULTS: No structural changes in the dentin-pulp complex of rats whose mothers were treated with fluoxetine hydrochloride were observed at either dose. CONCLUSIONS: Fluoxetine, at the doses administered during pregnancy in this study, did not alter the morphological development of the coronal dentin-pulp complex in their offspring.