Streptomycin is an aminoglycoside antibiotic used therapeutically as an antitubercular agent. It is also used as part of combination therapy for treatment of streptococcal or enterococcal endocarditis, plague, tularemia, and brucellosis. In the human, the aminoglycosides are well-established ototoxins in adults. Ototoxicity has also been recorded with streptomycin during pregnancy. Other aminoglycosides for which cases of fetal ototoxicity were recorded include dihydrostrepto-mycin and kanamycin, totaling about 28 cases. Streptomycin is a human developmental toxicant of very large size. It is highly hydrophilic with a high polar surface area. Streptomycin can act as both a hydrogen bond donor and acceptor. The drug has been studied by the pertinent human route in the guinea pig, mouse, and rabbit. Guinea pigs injected with up to 100 mg/kg/day late in gestation evidenced no developmental toxicity.