A GLC procedure for drug assay in commercial suppositories is described. Aminophenazone. d-propoxyphene hydrochloride, caffeine, chlorpheniramine maleate, lidocaine, phenacetin, fenalamide, and sodium benzoate were determined, in various associations, in three types of suppositories. Simultaneous determinations of up to five components were performed on the following columns: Column A, a mixed column of 2% polyethylene glycol (20,000) + 2% methyl silicone gum rubber on silanized diatomite impregnated with 5% KOH; Column B, a column of methylvinyl silicone gum rubber on silanized diatomite; and Column C, a mixed column of 0.4% isophthalic acid + 0.25% polyethylene glycol (20,000) on glass beads. The sample preparation procedure involves only a dissolution step. Precision and accuracy, calculated on simulated suppository preparations, were satisfactory.