To evaluate the efficacy of computer-tailored nutrition education with objective outcome measures. A 3-group randomized, controlled trial with posttests at 1 and 6 months post-intervention. Worksites and 2 neighborhoods in the urban area of Rotterdam. A convenience sample of healthy Dutch adults (n = 442). A computer-tailored intervention delivered on CD-ROM; a computer-tailored intervention delivered in print; and a generic information condition. Blood lipids (total, high-density lipoprotein, and low-density lipoprotein cholesterol, and triacylglycerol) were measured by analyzing venous blood samples. Linear mixed model procedure. There were no significant differences among the 3 intervention groups in total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triacylglycerol. Contrary to results based on self-report data, no effects of the computer-tailored interventions were found based on objective outcomes. This contradiction calls for a critical reflection on the use of computer-tailored nutrition education interventions and the need to improve those interventions. Furthermore, this study indicates that feasible methods are needed to objectively assess the impact of computer-tailored nutrition education interventions in free-living subjects. Copyright © 2011 Society for Nutrition Education. Published by Elsevier Inc. All rights reserved.