Purpose. Proliferative vitreoretinopathy is a serious complication of retinal detachment surgery in which retinal pigment epithelial cells abnormally proliferate within the vitreous cavity and under the retinal surface. Octreotide acetate, a somatostatin analog, has been shown to inhibit the cellular proliferation of a variety of cell types. The aim of this study was to investigate the effect of octreotide acetate on the growth of rabbit retinal pigment epithelial cells in culture.Methods. Retinal pigment epithelial cells were isolated from rabbits and maintained in culture. Cells were exposed to standard media or media supplemented with octreotide acetate 10-4M to 10-12M for five days. Each concentration of octreotide acetate was tested in quadruplicate.Results. Exposure of rabbit retinal pigment epithelial cells to octreotide acetate significantly inhibited proliferation with a peak effect at 10-8M. The effect of octreotide is biphasic with higher and lower concentrations having less effect than 10-8M.Conclusions. This study suggests that octreotide acetate may be useful in the treatment of proliferative vitreoretinopathy; however, the optimum therapeutic dose range for this drug may be narrow. Curr. Eye Res. 15: 909–913, 1996.