Abnormal clumsiness in otherwise normal children has been recognized for many years, but the causes of this disorder are heterogeneous or unknown. Although equivocal, there is some evidence from reaction time studies suggesting that clumsiness is associated with a defect in perception of movement in the kinaesthetic modality and of motor programming. In this experiment clumsy children and matched controls performed simple and choice kinaesthetic reaction time tasks with either simple or complex responses. The requirement to discriminate between kinaesthetic stimuli was found to increase reaction time more for clumsy than for control children, but increasing response complexity had no significant effect on the reaction time of either group. These results were interpreted as suggesting that clumsiness is associated with a perceptual defect in the kinaesthetic modality, but providing no support for an association of clumsiness with a defect of motor programming.