This article examines the use of pilocarpine hydrochloride for radiation-induced xerostomia in patients with head and neck cancer. Four randomized controlled trials involving 401 patients met the authors' predefined inclusion criteria and were critically appraised. Three studies used topical pilocarpine as a mouthwash. Outcome measurements were both quantitative and qualitative. The studies reported statistically significant differences in favour of pilocarpine-stimulated treatment groups. Subjective improvements in feelings of oral dryness, speaking and chewing were reported in all studies. However, sample sizes varied and in all cases sampling methods were poorly defined. The pilocarpine doses tested produced side effects, but those reported were easily tolerated. The persistent findings of symptomatic improvement following pilocarpine use merit consideration, but there is insufficient evidence from these studies alone to generalize results to the wider population.