The aim of this study was to study the effects of eight week of DNS exercises on posture, strength and trunk endurance in girls educable mentally retarded students. 26 mentally retarded female students were matched based on IQ score and divided into two groups of control and experimental . The experimental group participated in 24 training sessions. The variables of muscle strength and endurance, head and neck angle and back and lumbar arches of the subjects were evaluated by handheld Digital Dynamometer, sorensen test, side planck, planck, photogrammetry and flexible ruler, respectively. Data were analyzed by statistical analysis of variance for duplicate data (RN-ANOVA) . Exercise intervention resulted in a significant difference in strength and endurance of trunk and posture between the experimental and control groups (P>0/05). According to the present results, the use of DNS exercises in the process of physical rehabilitation of educable mentally retarded students is recommended.