The authors give the results of a horizontal study made in the course of the work carried out during 1988 in the Developmental Follow-up Unit of the University Hospital "Virgen Macarena" of Seville, making emphasis on the psiconeurological pathology detected and its relation to the cause consultation. A total of 443 children were studied, this number being 77% of the cases under control up to that time. 82.2% of the children (N = 364) were normal on neurological examination, with normal I.Q. at the last control. However, 147 of these children (33.2% of the total) had shown some transient neuromotor abnormality over the follow-up period. Of the total, 17.8% (N = 79) showed one more of the following permanent sequelae: Defects of mental development 15% (N = 67), Motor sequelae 8.8% (N = 39), Sensorial deficits 5.6% (N = 25), Convulsions 3.6% (N = 16), Important behaviour disorders 0.5% (N = 2). The presence of motor sequelae had a significant correlation with: CNS defects (p less than 0.001), Metabolic changes in the neonatal period (p less than 0.005), Neonatal convulsions (p less than 0.005), Isquemic-anoxic syndrome (p less than 0.05). Deficits of mental development are associated significantly with: Polimalformative syndromes (p less than 0.001), CNS defects (p less than 0.001) and with neonatal convulsions (p less than 0.001). The neuromotor abnormalities detected (in order of frequency) were: Changes in muscle tone (32%), Motor retardation (31.8%). Changes in prehensive behaviour (22%), Changes in motility (21%). Retarded expressive conduct (14.3%).(ABSTRACT TRUNCATED AT 250 WORDS)