Conduct problems were defined by teacher ratings of behavioral problems and/or antisocial behavior in the community. There was little overlap in the children identified by teachers and by the community. These two groups of children were at differential risk for adult mental disorder. Seventy-six percent of the males and 30 percent of females with childhood conduct problems had either a criminal record, a mental disorder, or both by age 30. Risk ratios for adult criminality and/or mental disorders, however, were greater for females than for males with a history of childhood conduct problems. Almost all of the mental disorders involved severe substance abuse. Mental disorders and crime were strongly associated among males with a history of childhood conduct problems. Study results thus support the hypothesis that children with conduct problems who are identified either by teachers or by community agencies are at risk for crime and substance use disorders as adults. 7 tables and 47 references