A multi-centre, randomized, single-blind, parallel-group clinical trial was undertaken in 50 patients (26 fenticonazole, 24 clotrimazole) with symptomatic vaginal candidiasis to compare the antifungal efficacy and tolerability of single-dose intra-vaginal treatment with a fenticonazole ovule (600 mg) or a clotrimazole vaginal tablet (500 mg). Assessment was by laboratory mycological investigation and symptomatic assessments for a period of 3 weeks from the day of treatment. Of the 50 patients, 43 (23 fenticonazole, 20 clotrimazole) returned for assessment 1 week after drug administration and 32 (17 fenticonazole, 15 clotrimazole) were re-assessed 3 weeks after drug administration. Both treatments resulted in very similar and highly significant improvements in symptoms, associated with disappearance of detectable Candida in approximately 70% of patients. There were no significant differences between treatments and no appreciable incidence of relapse during the 3-week period of observation. At the end of this period, 10 (59%) of 17 fenticonazole patients were totally disease-free, as compared with 10 (67%) of 15 patients after clotrimazole treatment. The cure rate observed was somewhat less than that previously seen when intra-vaginal cream formulations of the same two drugs were given on a multiple-dose basis. Both drugs were very well tolerated, with no reports of appreciable local or systemic adverse reactions to either drug.