The authors report the case of a women who took retinoids (Roaccutan®, isotretinoin) during the first trimester of pregnancy, and a therapeutic abortion was carried out. The interest in this case report lies in the determination of the concentration of isotretinoin and its metabolites (4-oxoisotretinoin, and tretinoin) in fetal tissues, using high performance liquid chromatography. The findings show the significant transplacental crossing of isotretinoin, an accumulation of 4-oxo-isotretinoin in the liver, and a low concentration of retinoids in the brain of this 4-month-old fetus. The authors emphasize that contraception must be used during retinoid treatment, and 4 weeks after retinoids have been stopped