During an epidemic of gastroenteritis which spread throughout New Zealand in 1978, 372 cases of nonbacterial illness were documented in children in Auckland during the months of June and July. A brief account is given of the clinical picture observed. Evidence from virological techniques suggests that some if not all cases were due to rotavirus. The severity of illness may have been greater than most observers to date have noted. From our observations we raise the possibility of air-borne spread, perhaps in addition to faecal-oral. We wish to emphasise that drugs play no part in the treatment of viral gastroenteritis, that home-made electrolyte solutions can be hazardous and that early intravenous therapy can be life-saving.