OBJECTIVES: A major challenge facing policy makers is the lack of economic evidence to guide their decisions about allocating health services for neck pain. Our objective was to evaluate the cost-effectiveness of the most commonly used neck pain treatments in Canada and the United States. METHODS: We conducted a cost-utility analysis with a decision-analytic model of 5 treatments for neck pain (exercise, cyclooxegenase-2 selective inhibitors, manipulation, mobilization, and nonsteroidal anti-inflammatory drugs [NSAIDs]) using a lifetime time horizon and adopting a health care system perspective. Model inputs included: estimates of the course of neck pain; background risk of adverse events in the general population; treatment effectiveness and risk of cerebrovascular, cardiovascular, and gastrointestinal adverse events; quality-of-life weights elicited from neck pain patients using the standard gamble; and direct and out-of-pocket costs. Costs were expressed in 2008 Canadian prices. The impact of beneficial and harmful treatment effects on health were expressed in quality-adjusted life years (QALYs). Cost-effectiveness was estimated with the incremental cost-effectiveness ratio (ICER). The probability that a given treatment was cost-effective was determined using a willingness-to-pay (WTP) threshold of $50,000 per QALY. RESULTS: Under a conventional threshold of $50,000 per QALY, manipulation was cost-effective compared to NSAIDs (the least costly alternative) (ICER=$25,123 per QALY). NSAIDs were most likely cost-effective at a WTP of