Congestive heart failure is a widespread cardiac disease in western countries. At present, the main measure for monitoring the level of pulmonary edema in telemedicine systems is weight, which is not a reliable indicator. The authors propose a novel bioimpedance telemedical system to monitor these patients. The system measures the resistivity of each lung using optimization methods and transmits the measurements via a modem to a call center. Preliminary results show that the measured resistivity values among healthy young patients are consistent and reproducible within 48 hours. The mean resistivity values in patients with pulmonary congestion were lower than those of the healthy patients: 887 [Omega*cm]+/-117 vs 1244 [Omega*cm]+/-87 (P<.01). The system is noninvasive, safe, and portable. It retrieves unique information correlated with the amount of fluid in the lungs and transmits the data to a medical call center in order to improve the diagnostics and treatment of congestive heart failure.