Trichophyton tonsurans is the leading cause of tinea capitis in the United Kingdom (UK) as well as causing tinea corporis. This organism has been linked to several outbreaks in the UK and abroad, and such outbreaks may be prolonged since T. tonsurans can be difficult to control. There remains an incomplete consensus in the literature on the optimal management of such outbreaks of this infection. Following notification that a child with T. tonsurans was identified at a day-care center in the UK, initial investigations identified nine cases of fungal infection involving children and staff over the previous 7 months. We report on the management of an outbreak of T. tonsurans tinea capitis and tinea corporis among children and staff in a day-care center. An outbreak control team with representatives from dermatology, microbiology, daycare center management, and the Health Protection Agency initiated case ascertainment by scalp inspection and brushing of all children and staff at the nursery. Two complete rounds of screening were required before the outbreak was declared over. Infection control measures included anti-fungal shampoo use, exclusion of identified cases for a short period, removal of shared items from the center, and enhanced decontamination of fomites. The outbreak, which lasted longer than 12 months, involved 12 children and 7 staff members. Of these, 12 cases were confirmed by positive fungal culture. T. tonsurans is difficult to manage, especially in childcare settings, but case ascertainment, appropriate treatment with oral agents, and sustained infection control measures can be effective in controlling such outbreaks. (author abstract)