Organochlorine compounds in milk were analyzed in samples collected over a nine-year period (1987-1995) from nursing mothers (N = 139) whose children were hospitalized for various disorders. All samples contained p,p'-DDE and PCBs; the median concentrations were 318 micrograms/kg milk fat and 220 micrograms/kg milk fat resp. Higher levels were found in mothers (N = 12) nursing neonates with impaired neurodevelopmental competencies or an inappropriate arousal reaction. No difference was observed between mothers nursing children with respiratory or gastrointestinal diseases, urinary tract infections or other infectious diseases, anemias, prolonged neonatal hyperbilirubinaemias or when children were with dermatological findings, congenital malformations or healthy.