Subretinal fluid was collected without contamination by blood by placing capillary tubes within drainage sclerotomies when retinal reattachment surgery was performed. All samples (N = 24) stimulated retinal pigment epithelial (RPE) cell migration and proliferation, but a wide range of activity existed (migration, 27.5% to 322.5% above baseline; proliferation, 7.5% to 318.3% above baseline). The correlation between migration- and proliferation-stimulating activity was not strong, suggesting the possibility that different agents are responsible for each. Several variables were examined for correlation with each activity, including age and sex of the patient; extent, duration, and height of the detachment; protein content of the fluid; and amount of cryopexy. It was found that proliferation-stimulating activity increased with the extent of detachment and duration of detachment, while migration-stimulating activity correlated best with amount of cryopexy given before drainage. These data suggest that retinal cryopexy enhances RPE cell migration activity in subretinal fluid, while RPE proliferation activity increases with the size and duration of detachment.