Objective: The aim of this study was to evaluate the efficiency of Ultraspeed, Ektaspeed Plus, and Insight radiographic films, and radiovisiography in detecting approximal carious lesions. Method and materials: Eighty approximal surfaces of 40 extracted human molars and premolars were evaluated. Radiographs of teeth blocks were taken with three different films and radiovisiography under standard conditions. The presence or absence of approximal caries was evaluated by three observers according to a five-point confidence scale. The actual status of each surface of the teeth was histologically determined from the teeth sections. Sensitivity, specificity, positive and negative predictive values, and likelihood ratios of the imaging modalities were calculated, and observer responses were assessed with Kendall's tau and Spearman's rho tests. Results: The sensitivity values for Ultraspeed, Ektaspeed Plus, Insight, and radiovisiography were 0.39, 0.48, 0.45, and 0.49, respectively, while the specificity values were 0.91, 0.88, 0.84, and 0.90, respectively. The difference in detecting approximal carious lesions between the systems was not statistically significant. Conclusion: This study suggests that there is no significant difference between the four imaging modalities in detecting approximal carious lesions.