Mycobacterium abscessus is emerging as an important cause of cutaneous infections in sporadic cases and outbreak settings. Although immunosuppressed or elderly patients are most commonly affected, in 2006 an outbreak of clinically distinct cutaneous lesions on the hands and feet caused by M. abscessus in a population of healthy children using a public swimming pool was reported. This article describes an outbreak of skin infection in a population of healthy Italian children attending the same school and using the same swimming pool. In January 2010 we identified three children with multiple, painful nodules on the palms and soles. M. abscessus was isolated from one child's lesions. A public health investigation was conducted and a team of dermatologists and public health officers visited all of the children; 514 children were screened and 29 cases were identified overall. All of the affected children had used the school's swimming pool. These children were treated with oral clarithromycin for 4 to 8 weeks. Because of the long period of time between the presentation and diagnosis of the first cases, the possibility that the number of cases may have been underestimated cannot be excluded. To our knowledge, this is the second largest reported cluster of M. abscessus skin infection suspected to be related to swimming pool exposure in a population of otherwise healthy children. It is unclear whether this disease is rare or should be considered as an emerging clinical entity.