In an ecological study of the distribution of self-injury in London, Canada, the authors found that self-injury occurred more frequently in the central areas of the city. Multivariate analysis revealed that living arrangements, such as high density of housing and single-person households, are closely associated with inflated rates on self-injury. Low socio-economic status is also related to self-injury but neither family status nor mobility are significant predictors. Ecological relationships such as these suggest directions for future research on individuals and may also be of direct use to planners who wish to locate treatment services advantageously.