The developmental course of spontaneous motility was investigated in a group of 26 fullterm infants, affected by mild to severe hypoxic-ischaemic encephalopathy. Serial 1-h videorecordings were carried out from birth to 15-22 weeks and a quality assessment of general movements (GMs) was made from a replay of the videos. Neurological follow-up of the infants were continued until at least 18 months of age; neonatal EEG and neuro-imaging techniques (US-scan, CT or MRI) were also carried out in all cases. The results indicate that perinatal asphyxia has important effects on the spontaneous motility of fullterm infants. Hypokinesis occurred very frequently during the first days of life, followed by a transient or prolonged (lasting longer than 15-22 weeks) abnormal quality of GMs. In the first 2 weeks the results of GM assessment did not correlate with the simultaneous findings of neurological examination, neuro-imaging and EEG, whereas they did when the results at 15-22 weeks were considered. The changes in spontaneous motility and especially GM developmental trajectories were good predictors of the neurological outcome. The predictive value of GM assessment was found to be similar to that of EEG and neuro-imaging, and better than neurological examination.