A variety of antimetabolites, steroids, and nonsteroidal anti-inflammatory agents were tested for their ability to inhibit rabbit dermal and conjunctival fibroblast proliferation in cell culture. Doxorubicin hydrochloride and fluorouracil produced notable inhibition in concentrations of less than 1 mg/L. Meclofenamate sodium and indomethacin produced notable inhibition at concentrations of 11 and 40 mg/L, respectively. Dexamethasone sodium phosphate and triamcinolone acetonide produced inhibition at 200 and 150 mg/L, respectively, but paradoxically increased proliferation almost two-fold at concentrations ranging from 1 to 30 mg/L under identical culture conditions. Methotrexate sodium demonstrated only limited effectiveness. This assay system may be a useful approach to drug selection in the treatment of a variety of ocular proliferative disorders. Fluorouracil may prove to be of significant value in the treatment of intraocular proliferative disorders.