Thirty-two diabetic patients with vaginal candidiasis were treated orally with 400 mg ketoconazole once daily for five days. At the end of the treatment period symptoms had disappeared and cultures for Candida were negative in 18 patients; a total of 28 reported improved symptoms. One month later 15 patients were still negative for Candida and 24 showed improved symptoms. The remaining 8 repeated the course of treatment; 6 became negative while 2 cases remained refractory to treatment. It was concluded that these encouraging results and low relapse rates indicate ketoconazole as a drug of first choice for candidiasis in patients with predisposing conditions such as diabetes.