A significant percentage of patients suffering from a stroke involving motor-relevant central nervous system regions will develop a spastic movement disorder. Hyperactivity of different muscle combinations forces the limbs affected into abnormal postures or movement patterns. As muscular hyperactivity can effectively and safely be treated with botulinum toxin type A (BoNT-A), we present a classification of spastic arm movement patterns to support BoNT-A therapy of arm spasticity. A few characteristic patterns can be distinguished that may be relevant for BoNT-A treatment. On the basis of a differentiated posture and arm movement analysis, five characteristic arm spasticity patterns (ASP I-V) were defined with respect to the position of the shoulder, elbow, forearm, and wrist joints. These patterns were verified using data from a worldwide noninterventional Upper Limb International Survey. By clinical observation, spastic arm postures in 94% of 665 poststroke patients could be assigned to one of these five ASPs. The most frequent pattern of arm spasticity was ASP III (41.8%) with internal rotation and adduction of the shoulder and flexion at the elbow coupled with a neutral positioning of the forearm and wrist, not the typical Wernicke-Mann position. These five different arm position patterns (ASP I-V) form the foundation of a common terminology and facilitate quick and understandable exchange of information with other physicians. Furthermore, utilization of these patterns may improve the dosing, goal setting, and outcome of the BoNT-A treatment of arm spasticity. (Contains 3 figures and 1 table.)