In recent years it has been standard practice to recommend that indirect ophthalmoscopy be carried out between six and nine weeks of age in very low birthweight infants to screen for the presence of retinopathy of prematurity (ROP). Following this recommendation we examined 85 infants over a two-year period. Acute ROP occurred in 29 (34%), and two (2.4%) developed cicatricial disease. One-third of infants were initially examined slightly earlier or later than the strict six to nine week limits, but all except three infants were examined between 35 and 42 weeks gestation. One infant born at 26 weeks gestation, was examined 'too late' in that she had stage 4 disease when first seen at 11 weeks of age. Recent information on the natural history of ROP, and confirmation of the efficacy of treatment with cyotherapy, suggested that the timing of an initial screening examination for ROP needed reassessment. From our experience and a review of the literature we recommended that infants of less than 1000 g birthweight or less than 28 weeks gestation have an initial examination at six weeks of age; for infants of 1000 to 1250 g birthweight or 28 to 30 weeks gestation examination continue to be at six to nine weeks of age; and for infants of more than 1250 g birthweight or 31 weeks gestation screening at six to nine weeks of age is only necessary if the infant has had an unstable course or prolonged oxygen requirements. Such a protocol would not place too great a burden on ophthalmological services and would direct efforts towards the group of infants most at risk of severe visual handicap.