The purpose of this study was to examine whether reading easily accessible fairy tales aloud to mentally retarded students had any effects on their vocabulary building.The subjects in this study were three selected mentally retarded students in a special class of S elementary school in the city of Busan. A program was conducted in 30 sessions for a nine-week period of time in three different stages including baseline, intervention and retention stages.The major findings of the study were as follows:First, the reading-aloud approach was effective at improving the receptive-language building of the students with mental retardation. Every student made progress in receptive vocabulary, as their receptive vocabulary was better in the retention stage than in the baseline one. And their receptive vocabulary in the retention stage was similar to that in the intervention stage, which implied the intervention remained effective.Second, the reading-aloud approach was effective at improving the expressive-language acquisition of the students with mental retardation. All the students made strides in expressive vocabulary. They had a richer expressive vocabulary in the intervention stage than in the baseline one, and their expressive vocabulary was similar in the intervention and retention stages, which showed the intervention continued to be effective.This study had some limitations, and there are some suggestions about how more accurate and generalizable results could be produced:First, only three students were examined in this study, which resulted in making it hard for the findings of the study to be generalizable. A larger number of students should be investigated to obtain more generalizable results.Second, picture materials were utilized in this study to assess the receptive and expressive vocabulary of the students. In order to check into whether students could generalize acquired vocabulary, realia evaluation should be implemented.Third, just mentally retarded students were investigated in this study. Future research efforts should be directed into finding out whether the intervention of this approach will have an effect on students with severe disabilities as well and how it should be applied to their education if it is effective.