Recently, we have seen the development of diagnostic tools based on the rationale that the measurement of electrical impedance of specific dermal zones might reflect the occurrence of pathological states in corresponding internal organs. Studies published lately have shown the diagnostic potential of this technique. We set out to evaluate the accuracy of this tool in diagnosing cancer. Our study group was composed of cancer patients visiting the Oncology clinic for a routine follow-up. All patients underwent conventional medical history and physical examination by a physician. We evaluated a device manufactured by Medex Screen Ltd. The device analysis was carried out by a physician who was blinded to the previous diagnosis. A third researcher compared the "conventional" diagnosis with the Medex device output using standard statistical analysis. Overall, 125 cancer patients were included in the study. When comparing Medex Screen diagnostic technique with the conventional methods of diagnosis for the various disorders we found a sensitivity of 76.2%, 78.7%, and 92.9% and a specificity of 95.0%, 90.7%, and 90.4% for lung, breast, and prostate cancer, respectively. Existence of metastatic disease or specific treatment did not affect the diagnostic properties of the described device. Although the exact mechanism is not entirely clear, measurement of electrical impedance of dermal-visceral zones has the potential to serve as a diagnostic and perhaps a screening tool for neoplastic pathologies. Further research should be conducted to create more evidence to support or dispute the use of this technique as a reliable diagnostic tool.