Ethanol was tested for teratogenicity in Drosophila melanogaster. Treatment consisted of rearing the fly larvae in media containing initial ethanol concentrations of 0%, 4%, 8%, or 14% by weight. Emerging flies were inspected for gross malformations. A low frequency of malformations was seen among controls (0.82%), increasing to 10.36% of emerging adults at the highest ethanol dose. The most common malformation involved the legs (segments missing or distorted or complete absence) and wings (uninflated, distorted, or absent). Less frequent defects included fused or missing mouth parts and missing halteres. Also, by exposing staged larvae to ethanol and examining the emerging flies, developmental stage sensitivity of Drosophila was investigated in terms of timing of treatment initiation. The results suggested that the incidence of defects increased with length of exposure. These results support the assumption that ethanol itself is the causative agent in ethanolinduced developmental toxicity and further support the use of Drosophila for developmental toxicity screening.