The purpose of the study was to investigate incidence, severity and types of motor problems in two groups of poor readers compared to good reading controls. A group of children with severe dyslexia referred to specialist evaluation, a teacher selected municipality sample comprising the 5% poorest readers, and a control group consisting of the 5% best readers were all assessed applying a norm-based, standardized measure by Henderson and Sugden 1992; ("The Movement Assessment Battery for Children." Kent: The Psychological Corporation). The three groups were compared with regard to total motor impairment scores as well as motor function within the areas of manual dexterity, ball-skills and balance. More than 50% of the children in both groups of poor readers showed definite motor coordination difficulties at or below the 5th centile, for which motor intervention is recommended. Children in both groups showed difficulties within the sub-area of manual dexterity in particular and also performed significantly worse than controls within the sub-area of balance, but not in ball-skills. The high incidence of motor coordination problems in the two groups of poor readers indicates that all children with reading difficulties should be screened for possible motor difficulties. (Contains 2 figures and 2 tables.)