Study Design.: An economic evaluation alongside a randomized controlled trial comparing behavioral graded activity (BGA) with manual therapy (MT). Objective.: To evaluate the cost-effectiveness of BGA in comparison with MT for patients with subacute neck pain from a societal perspective. Summary of Background Data.: Neck pain is common and poses an important socioeconomic burden to society. Data on the cost-effectiveness of treatments for neck pain are scarce. Methods.: A randomized clinical trial was conducted, involving 146 patients with subacute nonspecific neck pain. The BGA program can be described as a time-contingent increase in activities from baseline toward predetermined goals. MT consists of specific spinal mobilization techniques and exercises. Clinical outcomes included recovery, pain, disability, and quality-adjusted life-years (QALYs). Costs were measured from a societal perspective using cost diaries. The follow-up period was 52 weeks. Multiple imputation was used for missing cost and effect data. Uncertainty surrounding cost differences and incremental cost-effectiveness ratios was estimated using bootstrapping. Cost-effectiveness planes and cost-effectiveness acceptability (CEA) curves were estimated. Results.: BGA had no significant effect on recovery or QALYs gained in comparison with MT but pain and disability did improve significantly in the BGA group in comparison with the MT group. Total societal costs in the BGA group were nonsignificantly higher than in the MT group. Cost-effectiveness analyses showed that BGA is not cost-effective in comparison with MT for recovery and QALYs gained. Substantial investments are needed to reach a 0.95 probability that BGA is cost-effective in comparison with MT for pain and disability. Conclusion.: On the basis of the data presented, we consider BGA not cost-effective in comparison with MT. Copyright © 2011 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.