The purpose of the study was to examine the relationship between sleep patterns, motor proficiency and commonly co-occurring neurodevelopmental disorders in children, attitude to physical activity, mental health, and age. The study also looked at differences in sleep efficiency, as well as, perceived adequacy in physical activity between typically developing children and children with low motor proficiency. The sample consisted of 127 participants, 6-12 years old living in Perth, Western Australia. 51% participants were considered typically developing and 49% to have low motor proficiency. Motor proficiency, indications of Attention-Deficit/Hyperactivity Disorder, Autism Spectrum Disorder and anxiety/depression, adequacy in, or predilection for physical activity did not show a relationship to sleep efficiency. Significant differences between groups in sleep efficiency or adequacy in physical activity were not found. No interaction effect of neurodevelopmental disorders were identified. Sleep in children with movement impairments caused by neurodevelopmental disorders is an area where continued studies are of great importance. Although no relationship was identified in the current study, previous research has suggested sleep may play an important role for development and optimal everyday functioning. A better understanding of physical and psychological consequences and possible contributing factors of low motor proficiency in childhood is important as the risk of long-term dysfunction in emotional, cognitive and physical areas may be reduced in an optimal environment.