This paper deals with geographical and socio-ecological variations of pedestrian and cyclist accidents (n = 1233) among children (less than 15 years) on the Island of Montreal. The model includes variables on each child and his behavior when the accident happened and other temporal and spatial characteristics; environmental and socio-ecological data on the areas in which accidents occurred were also recorded. Descriptive, spatial and comparative analyses show specific patterns of location and occurrence of accidents. Factor analysis identifies the structure of characteristics linked to high accident areas for children's traffic accidents. A strong similarity between zone characteristics emerged from the factor analysis for both types of accident. Only a few census tracts (between 9% to 13%) are high accident areas, but they are very concentrated spatially, and for some of them (2% for pedestrians and 4% for cyclists) the rate is five to eight times higher than for the rest of the urban area. Population structure and density factors contribute 40% of the variation in accident rates. In terms of numbers, fewer children were injured as cyclists than as pedestrians, and more boys than girls are involved in these accidents. Accidents occur under good conditions of visibility and on straight streets. Parked cars in school areas are also a sign of danger. Difficulties in interpreting information on directions and speed of moving vehicles are associated with high accident frequencies, particularly for young pedestrians (6-7 years).