In Germany, kidney transplant patients form the largest group in solid organ transplantation. Improvements in diagnosing and treating medical problems and complications have lead to enhanced survival rates after transplantation. A crucial factor for the long-term success of kidney transplantations is the patients' life-long adherence to immunosuppressant medication. Numerous aspects influencing adherence have been investigated empirically. Across studies, social support has been shown to have an important impact on levels of patients' adherence to treatment. In kidney patients, lower levels of social support have been found to be a risk factor for non-adherence to immunosuppressant therapy, and impaired integration of the transplantation.