In a multicenter study of pediatric lawn-mower injuries (push or riding gas-powered machines), we reviewed 144 children at an average age of injury of 7.0 years; 77% were boys. Most injuries (92 of 104) occurred in the afternoon. The child was the machine operator in 36 cases, a bystander in 84, and a passenger in 21. The average hospital stay was 13.3 days with 2.6 surgeries per child. Amputations occurred in 67 children; 63 were unilateral and four bilateral; the most common level was the toes (63%). Blood transfusions were given to 35 children. Children injured by riding lawn mowers, when compared with those by push lawn mowers, were younger (5.4 vs. 11.0 years), less frequently the operator (15 vs. 60%), had longer hospitalizations (15.0 vs. 8.9 days), and required more surgeries (3.0 vs. 1.6) and blood transfusions (41 vs. 3%). Children with free flaps needed more transfusions (78 vs. 26%), and transfused children were younger (4.6 vs. 8.1 years), more likely to be bystanders (91 vs. 63%), required more surgeries (4.1 vs. 2.0), and were hospitalized longer (21.6 vs. 9.7 days). Soft-tissue infections occurred in eight of 118 and osteomyelitis occurred in six of 117 children. At an average follow-up of 1.9 years, there were 43 satisfactory and 84 unsatisfactory results. When excluding those children with amputations of digits, there were 42 satisfactory and 47 unsatisfactory results. If children younger than 14 years had not been permitted around lawn mowers, approximately 85% of the injuries in this report would have been prevented. Further public dissemination of the following information is needed: (a) children younger than 14 years should not operate lawn mowers, (b) children younger than 14 years should not be in the yard while the lawn is being mowed, and (c) no passengers, regardless of age, should be allowed on riding mowers.