The aim of this study was to investigate the combined effectiveness of mental imagery and biofeedback exercises on improving attention in girls with intellectual disabilities. The research method was semi-experimental and the research design included a repeated pre-test and post-test. 60 girls with intellectual disabilities aged 15 to 18 years from among the girls with intellectual disabilities in Tabriz exceptional high school voluntarily participated in this study. The participants were randomly divided into three experimental groups of 15 people each: mental imagery training, biofeedback, and a control group. In the first stage, the mental imagery ability of all individuals was assessed using the MIQR questionnaire, and individuals who lacked imagery ability were eliminated. Then, the first group (mental training group) performed the criterion skill in the form of internal imagery in each session; the second group underwent biofeedback training for ten sessions. The third group (combined) participated in the exercises for ten sessions in a combined manner. The continuous performance test scale was used to measure attention improvement in all three groups. Data were analyzed by multivariate analysis of covariance (MANOVA) at a p ≥ 0.05% level using SPSS21 software. The results showed that combined mental imagery and biofeedback exercises had a more positive and significant effect on improving attention in girls with intellectual disabilities than the results of the exercises alone.