INTRODUCTION: Inappropriate nonsteroidal anti-inflammatory drug (NSAID) use can occur by using more than one prescription or over-the-counter NSAID or exceeding the manufacturer's recommended dosage. There are risks associated with inappropriate NSAID use; however, the prevalence and predictors of inappropriate NSAID use are unknown. The study objectives are to estimate the prevalence of inappropriate NSAID use and identify characteristics associated with inappropriate use. METHODS: We identified 6877 patients at 2 Veterans Affairs Medical Centers through pharmacy records who filled 3 or more NSAID prescriptions in 6 months. We randomly selected 2535 patients and mailed them a survey about NSAIDs, gastroprotective medications, gastrointestinal (GI) symptoms, and pain. Inappropriate NSAID users either took 2 or more NSAIDs for 3 days or more or exceeded the maximum daily recommended dosage of 1 or more NSAID in the past week. Data were also collected from medical records. RESULTS: Approximately 1572 patients (62%) returned the survey, and 1250 reported NSAID use in the past week. Approximately 32% (n = 400) used NSAIDs inappropriately, including taking 2 or more NSAIDs (n = 173), exceeding the highest daily recommended dosage (n = 161) or both (n = 66). Being a minority (odds ratio = 1.62, P < 0.001) and having an income of $20,000 (odds ratio = 1.70, P < 0.001) or lesser both predicted inappropriate NSAID use. Inappropriate NSAID use was associated with more GI symptoms (β = 0.57, P < 0.001) and higher levels of pain (β = 0.85, P < 0.001). CONCLUSIONS: Inappropriate NSAID use is prevalent. Providers should consider counseling all patients about NSAID use, especially patients with GI problems or pain problems.