Twenty-four patients with severe interdigital toe web infections and no evidence of dermatophyte colonization received randomized treatment with either econazole nitrate (Spectazole) or its vehicle. Of the patients treated with econazole nitrate, 88% had good to excellent responses, whereas no patient treated with the vehicle showed improvement. The total aerobic flora in the econazole group decreased 93%, with decreases in the large-colony diphtheroids, lipophilic diphtheroids, and gram-negative bacteria. The results of this study demonstrate that the antibacterial activity of econazole nitrate makes it an effective agent for the treatment of severe interdigital bacterial infections uncomplicated by dermatophyte colonization.