The efficacy of miconazole in the treatment of mycotic vulvovaginitis was investigated in a blind study on 230 consecutive unselected patients. All had subjective complaints and positive cultures, and 166 had endocrinologic conditions predisposing to the development of candidiasis. Nine different yeasts were identified before treatment, the great majority being Candida albicans. All miconazole treatment regimens were significantly better than the control vehicle alone. The 2 per cent miconazole cream, producing about 95 per cent cures, was significantly (p = 0.011) more effective than the 1 per cent cream, than nystatin (p < 0.0001), and than the control vehicle (p < 0.0001). But the cure rates were similar after one and two daily applications of the 2 per cent cream for one or two weeks. Local tolerance was always excellent. There were no reports of irritation or other adverse reactions.