A sensorineural hearing loss was found in two members of a single family. Both mother and son had previously received streptomycin therapy. Although other causes of hearing loss in the son could not be eliminated, evidence is presented that supports streptomycin toxicity as the cause. To our knowledge, this represents the eighth such family in which a hearing loss secondary to streptomycin therapy has been described. It is believed that in these cases there is an increased sensitivity to this drug.