Although reports on reproductive disturbances among occupational groups of electrical workers have been discussed, few studies have focused explicitly on the children of workers employed in the power industry. Birth outcome and cancer in the offspring of fathers who were exposed to electric and magnetic fields at time of sperm production were studied in two cohorts. In Study 1, male occupation in the power industry was identified in censuses. Study 2 is a prospective cohort study of newly employed power industry workers. Birth data were obtained by record linkage between censuses and several available health registers in Sweden. Multiple births, birth weight, sex, survival, congenital malformations, and cancer have been analyzed with relation to the father's exposure to electric and magnetic fields one year before the child was born. There were six cancer cases among infants in the exposed group (2.4 expected) and six in the unexposed group (3.2 expected) in Study 1. Jointly, the 12 cancer cases found among the infants were more than expected (P = 0.02). However, this total excess may be random. No cancer cases were observed in the prospective study. For chromosomal abnormalities, such as Down's syndrome, one case was observed among infants of exposed fathers and three cases among unexposed fathers in Study 1. In Study 2, no cases were observed. There was a slightly higher proportion of malformation diagnoses among infants of exposed fathers than among infants of unexposed fathers in Study 2, but this could be random (odds ratio = 1.59; 95% Confidence interval 0.43-1.48). No clear-cut effects on infants fathered by men who were exposed to electric and magnetic fields around the time of sperm production could be seen in these two studies.