Sensory integration training plays a crucial role on the attention span and motor skills of students with Down syndrome. The present research aimed to investigate the effect of sensory integration training on the attention span and motor skills of students with Down syndrome. Methods: This was a quasi-experimental research with a pretest, posttest design and control group. Participants were 28 male students with Down syndrome from two exceptional schools in Tehran. The samples were selected by convenience sampling method. Students were randomly divided into the control and experimental groups and each group consisted of 14 students. A 10-session sensory integration training was provided to the experimental group, while the control group did not receive this training. The Stroop color-word test and Bruininks Oseretsky Test of Motor Proficiency were used for measuring the attention span and motor skills of the students. The obtained data were analyzed using MANCOVA. Results: MANCOVA indicated a significant difference between the attention span and motor skills in the experimental group after the training sessions (P<0.0001). Discussion: Sensory integration training led to the improvement of attention span and motor skills of students with Down syndrome. Therefore, Sensory integration training could have positive impacts on the attention span and motor skills of students with Down syndrome.