The authors face the problem of accuracy, specificity and sensitivity of double-contrast arthrography in meniscal injury of the knee. They report the results obtained in a clinical-statistic and retrospective investigation on 206 patients. The final diagnoses were obtained by arthrotomy (105 cases) by arthroscopy (70 cases) and clinically with a follow-up of 6 months (31 patients). Diagnostic accuracy (94,5%), sensibility (92%), specificity (98,7%) and predictive values on positives (99%) and negatives (87,5%), confirm double-contrast arthrography as a highly accurate examination. A specific diagnosis can be made only when the diagnostic modalities are correctly applied and the arthrographers are qualified.