Information regarding conditions during pregnancy and delivery was obtained by extensive interviews with mothers to left-handed and right-handed students. Using the same criterion as van Strien, Bouma and Bakker (1987) for defining birth stress, the present study did not replicate their findings of higher frequency of reported birth stress in left-handers. The difference in outcome was ascribed to differences in recruitment of subjects, the present sample constituting a majority of left hand writers from a population of 921 students, while the van Strien sample was less well defined. The present study was extended by comparing left-handed and right-handed subjects (separated for sex) with and without birth stress, on verbal and nonverbal abilities, and on eye dominance, early learning difficulties and familial sinistrality. Left eye dominance was more frequent in male left-handers with birth stress. Birth stress alone had negative effects on cognitive performance, different for males and females.