The present research aimed to develop the Checklist of Psychomotor Activities (CPA) to measure psychomotor development in 5-6 year old children. We recruited 694 preschool children in the province of Albacete; their teachers were trained to use and complete this instrument to gather data for testing its psychometric properties (reliability, and content, construct, and discriminant validity). The CPA is composed of three subtests measuring children’s performance in motor, perceptual, and emotional–social aspects of psychomotor functioning. To gather evidence of content validity, we applied the Delphi method, based on the comments of seven judges. We assessed construct validity with confirmatory factor analysis, and we tested discriminant validity by comparing the scores of premature and typically developing children and separate groups of children defined by their body mass index. We found adequate item consistency on each scale and evidence of validity from the various methods outlined. We conclude that the CPA is an effective and comprehensive tool for the assessment of psychomotor skills in children at this important stage of development.