Abstract: Objective To evaluate the internal reliability of Psychosocial Function Evaluation for mental disabled people in day care unit. Methods 16 participants were evaluated twice by the same rater (social worker) in the unit at the Permanent stage and the Steering stage. Results Cronbach's α was greater than 0.7 in the both evaluation. The Spearman correlation coefficient between each dimension and total score were between 0.502 and 0.869. Conclusion The internal reliability of Psychosocial Function Evaluation is satisfactory for mental disabilities.

Key words: psychosocial function, assessment, internal reliability