Possible determinant factors that may increase the risk of the occurrence of retrolental fibroplasia (RLF) were analyzed in 80 infants born in 1975 and 1976 with birth weights between 501 and 1,500 gm and who survived. Active and/or cicatricial RLF occurred in 27 (33.8%) infants and the factors significantly associated with RLF were: gestational age (P less than .001); apnea requiring bag and mask resuscitation with oxygen (P less than .001); septicemia (P less than .005); degree of illness; blood transfusion; and mechanical ventilation. Severe cicatricial RLF developed in eight (10%) infants (grades 2 to 5). In the group of infants all of whom had apnea which required resuscitation, septicemia was also significantly associated with RLF (P less than .01). A highly significant association between RLF and severe myopia (P less than .001) was found in follow-up in all infants. Data show a resurgence and high incidence of RLF in low birth weight infants who survived. Infants with these factors should be considered to have greater risk for the occurrence of RLF and ophthalmologic examination prior to, and within three months following discharge is recommended.