We describe the state of the art of Prechtl's method for the qualitative assessment of general movements as a diagnostic tool for early detection of brain dysfunction. After discussing the optimal technique for video recording general movements in preterm, term and young infants, attention is focused on the proper analysis of this spontaneous motor pattern. Recently, a group of active researchers in the field reached consensus on the various qualities of normal and abnormal general movements. These definitions are reported here in full. Since it is a newly introduced method careful investigation into its reliability is required. Various groups of investigators have obtained data which demonstrate the robust character of the method (interscorer agreement: 78-98%). Finally, we discuss the validity of this early assessment method on the basis of the reports published so far. While the method's sensitivity is similar in all age groups studied (preterm, term, first month, second month, and third month age epochs), and averages 94.5%, the specificity of the method is age-dependent. It is low during the early ages, increases gradually and reaches 82 to 100% at 3 months post-term. This phenomenon is explained by spontaneous recovery of early dysfunction. In contrast, consistent abnormalities of general movements are linked to neurological deficits found at the 2 year follow-up.