Magnetic resonance imaging (MRI) findings have been reported for specific clinical cerebral palsy (CP) subgroups or lesion types but not in a large population of children with all CP subtypes. Further information about the causes of CP could help identify preventive strategies. To investigate the correlates of CP in a population sample and compare clinical findings with information available from MRI brain studies. Cross-sectional, population-based investigative study conducted in 8 European study centers (North West London and North East London, England; Edinburgh, Scotland; Lisbon, Portugal; Dublin, Ireland; Stockholm, Sweden; Tübingen, Germany; and Helsinki, Finland). Five hundred eighty-five children with CP were identified who had been born between 1996 and 1999; 431 children were clinically assessed and 351 had a brain MRI scan. Standardized clinical examination results, parental questionnaire responses, MRI results, and obstetric, genetic, and metabolic data from medical records. Important findings include the high rate of infections reported by mothers during pregnancy (n = 158 [39.5%]). In addition, 235 children (54%) were born at term while 47 children (10.9%) were very preterm (<28 weeks). A high rate of twins was found, with 51 children (12%) known to be from a multiple pregnancy. Clinically, 26.2% of children had hemiplegia, 34.4% had diplegia, 18.6% had quadriplegia, 14.4% had dyskinesia, 3.9% had ataxia, and 2.6% had other types of CP. Brain MRI scans showed that white-matter damage of immaturity, including periventricular leukomalacia (PVL), was the most common finding (42.5%), followed by basal ganglia lesions (12.8%), cortical/subcortical lesions (9.4%), malformations (9.1%), focal infarcts (7.4%), and miscellaneous lesions (7.1%). Only 11.7% of these children had normal MRI findings. There were good correlations between the MRI and clinical findings. These MRI findings suggest that obstetric mishaps might have occurred in a small proportion of children with CP. A systematic approach to identifying and treating maternal infections needs to be developed. Multiple pregnancies should be monitored closely, and the causes of infant stroke need to be investigated further so preventive strategies can be formulated. All children with CP should have an MRI scan to provide information on the timing and extent of the lesion.