The effective use of aqueous and oily pilocarpine was studied in 19 glaucomatous eyes. The aqueous drops were used 4 times a day while the oily drops were used only twice. It was found that the oily drops were better than the aqueous drops in lowering the mean intraocular pressure and the maximum pressure reached during the day. no statistically significant difference was found between the 2 pilocarpine treatments in the reduction of daily variation of intraocular pressure. It is felt that oily drops used only twice a day would lead to better patient compliance and better control of chronic simple glaucoma.