PURPOSE: Detection and determination of tendon injury in the finger or hand is not easy. Therefore, we aimed to study and evaluate the accuracy and the effectiveness of ultrasonography for the diagnosis of finger tendon injury. METHODS: In this study, we enrolled patients, regardless of age and sex, with lacerations on their fingers. Patients with invisible wounds were excluded. We evaluated the accuracy and the effectiveness of ultrasonography and compared the results obtained from ultrasonography and with those obtained by visual observation of the injuries. RESULTS: The sensitivity, the specificity and the accuracy of ultrasonography were found to be 66.7%, 100% and 91.3%, respectively (p<0.001) while those of physical examination were 71.4%, 98.3% and 91.3%, respectively. Small differences were observed between the sensitivities and specificities of the two examinations; however, the accuracies were the same (p<0.001). The area under the receiver operating characteristic (ROC) curve, which was used for diagnosis of tendon rupture using ultrasonography, was found to be 0.985 (95% confidence interval CI: 0.929-0.999),while that of physical examination was 0.938 (95% CI: 0.861-0.980). CONCLUSION: Ultrasonography can be used an effective diagnostic tool for patients with finger tendon injury.