The efficacy and safety of oral fluconazole versus a polyene regimen in preventing mycoses in neutropenic patients was compared. Patients with haematological malignancy or bone marrow transplantation received as antifungal prophylaxis either fluconazole 200 mg daily or a regimen consisting of clotrimazole trouches 10 mg twice daily with mycostatin, 500,000 i.u. four times daily, benadryl and cepacol mouthwash. Ninety patients at risk for fungus infection were evaluable. Four of 42 patients (9.5 %; confidence interval 2 %–23 %) on fluconazole and 17 of 48 patients (35.4 %; confidence interval 22 %–52 %) (p<0.01) on="" the="" clotrimazole="" regimen="" developed="" a="" clinically="" significant="" fungal="" infection,="" including="" 3="" (7.1="" %)="" and="" 11="" (22.9="" %)="" patients="" respectively="" who="" had="" severe="" fungal="" infection,="" mainly="" pulmonary="" aspergillosis.="" death="" directly="" due="" to="" a="" fungal="" infection="" within="" 100="" days="" of="" the="" start="" of="" prophylaxis="" occurred="" in="" 2="" of="" 42="" patients="" (4.8="" %)="" and="" 9="" of="" 48="" patients="" (18.8="" %)="" respectively=""><0.06). kaplan-meier="" analysis="" showed="" that="" the="" chance="" of="" survival="" on="" fluconazole="" was="" statistically="" greater="" than="" for="" the="" clotrimazole="" regimen=""><0.04). a="" decrease="" of="" candidal="" colonisation="" of="" the="" gastrointestinal="" and="" genitourinary="" tracts="" occurred="" only="" in="" patients="" receiving="" fluconazole.="" no="" significant="" toxicity="" occurred.="" a="" 200="" mg="" daily="" dose="" of="" fluconazole="" given="" to="" these="" patients="" thus="" appears="" to="" be="" well="" tolerated="" and="" to="" provide="" a="" protective="" effect="" against="" the="" development="" of="" fungal="" infection="" and="" death="" from="" severe="" fungal="">