The early infancy is especially affected by moniliasis in pediatrics. The causes are: broad spread of Candida albicans in the environment of these children, a growing immunity, the immaturity of the skin and an insufficient candida-static activity of the serum. The prematures and the newborns with an irregular birth are especially endangered. This danger is increased by simultaneous antibiotic therapy. The arising mycosis can reach from the relative harmless mouth- and diaper-thrush to serious septic diseases. An effective therapy therefore is very much desired. As new efficacious medicaments the derivates of imidazol, Clotrimazol, have proved satisfactory for the treatment of mycoses. It is as Canesten marketed. The drug possesses a strong activity against numerous fungi, some protozoa, and bacteria. In this paper it is reported on own pharmacokinetic and therapeutic investigations with Clotrimazol. The substance has been very useful for the treatment of mouth- and diaper-thrush. Clotrimazol was administered as BAYb 5097 peroral and local as Canesten -solution 1% and -cream 1%. There were 171 treatments carried out. Essential side-effects were not observed.