This study examined the effects of two training methods (interest-based method vs. traditional method) in improving independent problem solving performance of students with mild mental retardation representing three cultural backgrounds (African-American, European-American and Nigerian) as measured by Edeh Scale of Interpersonal Problem Situations. Students were randomly assigned to one of the three treatment groups: Interest-based method vs. Traditional method vs. Control group. Significant treatment group main effects were found in problem solving performance. Results indicated that the participants in the interest-based method significantly generated higher posttest scores in independent problem solving responses than both the participants in traditional method and the control groups. Participants in the traditional method significantly generated higher posttest scores in independent problem solving responses than participants in the control group. Three months follow-up showed that higher percentage of students in interest-based method maintained the independent problem solving skills than both the participants in traditional method and the control groups. Curriculum implications were addressed. (Contains 5 tables and 3 figures.)