OBJECTIVES: Given the increasing frequency of obesity and the costs associated with it, it is vital to determine which interventions are effective and cost-effective versus the alternatives. A crucial step in both cases is a critical appraisal of the literature. This study examined the quality of economic evaluations (EE) of obesity interventions using a quantitative approach. METHODS: Economic evaluations were selected using the NHS Economic Evaluations Database (NHS EED, York UK)(1995-2006). Quality was based on the method by Chiou (2003) because its development involved many health economists and it provides an overall quality score (range:-1100) using 16 criteria. Associations between study characteristics and quality were examined using regression analysis. Characteristics included publication year, type of intervention (including diet, behaviour, medicine, surgery, combined intervention), source of effectiveness data (single study, literature review), country of evaluation, and source of funding. RESULTS: Thirty-four EEs were identified and all of them fulfilled only some criteria. The most common weaknesses were no discussion of potential biases and inappropriate time horizon or discounting method. Mean overall score was 52 (range:24–76, SD:13). Recent EEs were better than older ones (+1.5 points/year) and European EEs were better (15 points) than non-European ones. Source of effectiveness data and source of funding were not associated with quality after adjustment for year and country. Type of intervention was never associated with quality. CONCLUSION: The average quality of EEs seems moderate given a score of 52/100. There is much room for improvement and examination of individual criteria is indispensable in achieving this. Determination of overall quality scores is not an adequate substitute for a critical appraisal. Sometimes a single weakness in a “very good” EE can be fatal and render cost-effectiveness estimates useless. In contrast, elements of a “poor” EE can be valuable when determining the cost-effectiveness of an intervention.