Medical sensor networks play a vital role for real-time health care monitoring of telemedicine based applications. Telemedicine provide specialized healthcare consultation to patients in remote locations. We use electronic information and communication technologies to provide and support healthcare when the distance separate the participants. In order to ensure the privacy and security of patient's critical health information, it is essential to provide efficient cryptography scheme. This paper presents a novel Mamdani based Bio-Key Management (MBKM) technique, which assures real time health care monitoring without any overhead. We present the simulation results to show that the proposed MBKM scheme can achieve greater security in terms of performance metrics such as False Match Rate (FMR), False Non Match Rate (FNMR), and Genuine Acceptance Rate (GAR) than other recent existing approaches. © 2015 IEEE.