The present invention is directed to a system and method for monitoring the physiological parameters of an organ or tissue during and after surgery. The system has a probe and a monitoring unit. In one embodiment the probe includes features for convenient, fixed and releasable attachment to surgical drains without interfering with their normal fluid-draining function while utilizing their suction to enhance the probe-to-tissue interface for improved sensing. An applicator is provided to facilitate such attachment. The monitoring unit which controls the sensors of the probe includes a processor to process, record and display the sensor data. This system may be valuable for monitoring transplanted organs and tissue grafts during the critical postoperative period when most of the clinical complications, such as vascular thrombosis, may occur.