In a controlled clinical study, we investigated the effects of behavioral treatment on postural and gait initiation problems in idiopathic Parkinson's disease (PD). Comparable groups of patients received behavioral therapy (experimental group, n = 15) and nonspecific psychological treatment (control group, n = 14) for 10 weeks. We monitored various variables reflecting properties of posture and gait initiation by using an optoelectronic motion analyzer (electronic movement analysis system, ELITE). A clinical blind to group membership of the patients assessed PD severity with the Unified Parkinson's Disease Rating Scale (UPDRS) before and after the treatment period. ELITE measures of postural stability and movement initiation revealed treatment-specific effects. In addition, UPDRS motor scores showed significant improvement only after behavioral treatment. We conclude that behavioral treatment in Parkinson's disease may improve motor disabilities in moderately advanced PD patients.