Objective: The aim of this study was to demonstrate the effect of low-powered magnification on the accuracy of caries detection and to compare it to the accuracy of unaided vision. Method and materials: Five dental models were prepared with extracted, unrestored, human permanent premolars, molars, and canines. Dental examinations were undertaken in simulated clinical conditions by seven dentists using both unaided and magnified vision. A true diagnosis was obtained by histologic sectioning, thereby allowing diagnostic accuracy to be calculated. Results: The sensitivity of diagnosis, representing the percentage of diseased sites found correctly, was significantly greater when magnification was used. There was no statistically significant difference in the specificities, or percentages of correctly identified healthy sites, between magnification and unaided vision. Conclusion: Magnification, although not perfect, improved significantly on the accuracy of diagnosis and can therefore be recommended for caries detection.