OBJECTIVES: In patients with uninvestigated dyspepsia, a common initial management strategy in primary care is to prescribe a course of empiric antisecretory therapy and to refer those patients who do not respond for endoscopy. The objective of this research was to evaluate the effects of an empiric course of antisecretory therapy on dyspepsia-related health in patients with uninvestigated dyspepsia. METHODS: We conducted a double blind, randomized, placebo-controlled trial in which patients with uninvestigated dyspepsia were randomized to a 6-wk course of omeprazole 20 mg p.o. b.i.d. versus placebo capsules p.o. b.i.d. and followed over 1 yr. The patients were at least 18 yr old with at least a 1-wk history of dyspepsia without alarm features. Dyspepsia-related health was measured using the Severity of Dyspepsia Assessment (SODA), a valid, reliable, disease-specific outcome measure. The primary outcome was treatment failure, defined by a SODA Pain Intensity score ≥29 (scores, 2–47) during follow-up. Patients who were treatment failures underwent endoscopy. RESULTS: We enrolled 140 patients. The mean age was 51 yr, and seven (5%) were women. At 2 wk there were fewer treatment failures in the omeprazole group: 12 of 71 patients (17%) in the omeprazole group failed compared with 24 of 69 (35%) in the placebo group ( p = 0.037, log rank test). Also, at 6 wk there were fewer failures in the omeprazole group: 21 of 71 patients (30%) in the omeprazole group failed compared with 31 of 69 (45%) in the placebo group ( p = 0.067, log rank test). However, at the 1-yr follow-up, there was no significant difference in treatment failure rates in the two groups: 37 of 71 patients (52%) in the omeprazole group failed compared with 41 of 69 (59%) in the placebo group ( p = 0.28, log rank test). CONCLUSIONS: In patients with uninvestigated dyspepsia, as compared with a strategy that would entail prompt endoscopy for all patients, an initial 6-wk course of either placebo or omeprazole reduces the need for endoscopy over a 1-yr follow-up. Compared with placebo, an initial 6-wk course of omeprazole delays, but does not reduce, the need for endoscopy. For proton pump inhibitor therapy to reduce the need for endoscopy, it may need to be given continuously.