Invasion of keratin of the hair by dermatophytes is a rare event after puberty. A study of 2200 patients affected by various mycotic cutaneous infections during 6 years of observation brought to our attention three cases of tinea capitis in adults. Confirming the studies of other authors, we also found that this disease mostly affected females. In all cases the isolated aetiological agent was Microsporum canis, the fungus species most frequently responsible for tinea capitis in Italy.