The ototoxicity and nephrotoxicity of netilmicin were compared with those of dibekacin, kanamycin and amikacin using rabbits. Groups of 5 rabbits each were given doses of 50 or 100 mg/kg of either one of the four drugs for 30 days, and 10 days after the last injection, all animals were prepared for histopathological studies. Results show the least ototoxicity of netilmicin in comparison to the other three antibiotics. It has been concluded that the low ototoxicity of netilmicin is due not to its lack of accumulation in the perilymph but to its low toxicity to the hair cells.