Over the past 3-4 decades, numerous studies have been published evaluating interventions targeted at healthcare providers, at patients, or at both patients and healthcare providers, which are designed to, in some fashion, improve the provider-patient relationship and thereby enhance patient health outcomes. This article synthesizes findings from 14 literature reviews of relevant studies published between 1991 and 2007. Findings indicate that interventions aimed at physicians and other providers have consistently produced positive effects on provider communication behaviors and interpersonal skills. However, only moderately positive effects on patient satisfaction, and limited impact on patient healthcare behaviors such as compliance, appointment adherence, and resource use were found. Effects on primary medical outcomes were minimal although some positive effects on secondary medical outcomes such as quality of life were obtained. Patient-targeted interventions also showed consistently positive effects on patient-physician communication in addition to enhanced patient participation in decision making. Effects on patient primary medical outcomes were limited, and weak effects on patient satisfaction were obtained. Characteristics of studies and training programs that may have influenced outcomes are discussed, as are practical impediments to promoting better physician-patient communication in clinical practice.