To investigate the presence of three C-C chemokines (monocyte chemotactic protein-1 [MCP-1], macrophage inflammatory protein-1alpha [MIP-1alpha], and MIP-1beta) in vitreous samples from eyes with proliferative vitreoretinopathy (PVR), proliferative diabetic retinopathy (PDR), or retinal detachment (RD). Vitreous samples were obtained and assayed by solid phase enzyme-linked immunosorbent assay for the chemokines MCP-1, MIP-1alpha, and MIP-1beta in a prospective study of 43 consecutive patients. Eighteen samples from cadaveric control eyes were also assayed. Monocyte chemotactic protein-1 was detected in all samples. The vitreous of eyes with vitreoretinal disorders showed significantly higher levels than the vitreous of cadaveric control eyes (P < or = 0.05). Median level (5th-95th percentile) in the PVR cases (n = 20) was 890.18 pg/mL (286.04-1806.20); in RD (n = 8), 296.69 pg/mL (171.44-1310.02); and in PDR (n = 15), 434.60 pg/mL (124.56-1092.94). In the cadaveric control eyes (n = 18), median level was 83.97 pg/mL (26.09-208.38). Macrophage inflammatory protein-1alpha and MIP-1beta were not detected in any samples. Monocyte chemotactic protein-1 might be involved in the recruitment of macrophages and monocytes into the vitreous of eyes with proliferative vitreoretinal disorders.