Pilocarpine and placebo tablets were administered for 90 day periods in a double-blind, sequential crossover trial to 12 patients with postradiation xerostomia. Salivary flow was measured by two techniques, symptomatic change and adverse side effects were also recorded. Nine of the 12 patients showed marked improvement by two or more criteria while taking pilocarpine. None of the 12 patients showed meaningful improvement while on placebo. Side effects were minimal and easily controlled. These results show that pilocarpine is effective in relieving the signs and symptoms of postradiation xerostomia.