The purpose of the present study was to find out if formerly premature babies (birth weight less than or equal to 1,501 g) show differences in their neurological, psychological and linguistic development of school-age when compared to children without perinatal problems. Discrete neurological dysfunctions (clumsy child syndromes, discrete hemi-syndromes) and left-handedness were found significantly more frequently in the premature group. The test psychological investigation of the intellectual development and the development of language did not reveal significant differences between the two groups. Also with regard to the cognitive partial functions (attention, visual differentiation, serial memory performance and visuomotor coordination) the prematures were significantly behind only in serial memory performance. On the other hand the results of the psychological investigations were significantly worse in children of lower social classes independent of birth weight.