The present study deals with a case of a 40-day-old girl with kerion Celsi caused by Microsporum canis. The source of the infection were the parents who presented tinea corporis caused by M. canis. Systemic treatment was carried out with terbinafine and complete recovery was achieved. Tinea capitis is unusual in children during their first year of life and its evolution towards kerion is very rare in newborns.