Frequency of suicide ideation and attempts in 791 children with autism (1-16 years), 35 nonautistic depressed children, and 186 typical children and risk factors in autism were determined. Percent of children with autism for whom suicide ideation or attempts was rated as sometimes to very often a problem by mothers (14%) was 28 times greater than that for typical children (0.5%) but less than for depressed children (43%). For children with autism, four demographic variables (age 10 or older, Black or Hispanic, lower SES, and male) were significant risk factors of suicide ideation or attempts. The majority of children (71%) who had all four demographic risk factors had ideation or attempts. Comorbid psychological problems most highly predictive of ideation or attempts were depression, behavior problems, and teased. Almost half of children with these problems had suicide ideation or attempts. All children with autism should be screened for suicide ideation or attempts because ideation and attempts in autism are significantly higher than the norm and are present across the spectrum. This is especially important for children who have the demographic and comorbid risk factors, many of which can be targeted for intervention to reduce and prevent suicide ideation and attempts. (Contains 3 tables.)