The expeditious growth of the wearable and implantable body sensors and wireless communication technologies have provided both inspiration and motivation for increasingly development of m-healthcare information systems as a promising next generation e-health system. In m-healthcare systems, the authorized mobile patients with the same disease symptoms can constitute a social group to share their health condition and medical experience. The privacy of social communication transferred over open wireless channels is an essential system requirement. Furthermore, the m-healthcare system on contrary to the traditional e-Health system allows mobile patients to move across distinguished location domains during different time periods. The mobility of patients considerably increases the cost of key management in terms of communication overhead if it is addressed with a naïve solution such as treating as a leave in the old location and a new join in the visited location. This paper proposes a privacy-preserving scheme, which maintains the secrecy of patients’ personal health information using secure group communication in m-healthcare information systems while supporting mobility of patients. The scheme is highly scalable, and treats patients’ mobility with the minimum rekeying cost, as such efficiently preserve secrecy of communication between patients associated with a social group. The security properties of the proposed scheme as well as its performance based on simulation experiments are evaluated. The experimental results demonstrate that the proposed scheme outperforms the existing solution in terms of communication overhead.