Background: Preschoolers with developmental disabilities are referred to occupational therapy due to their decreased participation in daily life occupations. The purpose of this study was to evaluate the improvement in preschoolers’ participation and sensory-motor abilities following an occupational therapy intervention. Materials and Methods: A prospective cohort study of 38 preschoolers and their parents was conducted using an interrupted time-series design, including assessments at three time points: base line (upon referral to an occupational therapy assessment), pre-intervention, and post-intervention after 9–12 sessions of occupational therapy interventions. Children were evaluated with the Developmental Test of Visual–Motor Integration, as well as the balance and fine motor precision sub tests of the Bruininks–Oseretsky Test of Motor Proficiency. Parents completed the Children’s Participation Questionnaire and the Child Performance Skills Questionnaire. Each intervention session was documented by the therapists using the Documentation of Occupational Therapy Session Intervention form. Results: Significant improvement in children’s sensory–motor abilities were found in balance, visual integration, and fine motor precision post-intervention. There were also improvements in the measures of diversity, children’s independence, and parental satisfaction. Conclusions: A short-term occupational therapy intervention applied to preschoolers with developmental disabilities is effective in .

improving their sensory–motor abilities, as well as in promoting their participation in daily activity.