In Lithuania there are enough data about the prevalence of risk factors for chronic diseases among the general population and specific age groups (Domarkienė et al., 2003; Vaičaitienė, 2006; Kristenson, 1997), but there is still a lack of research analyzing the prevalence of health risk behaviour and the effectiveness of the psychological methods aimed to change this type of behavior. The findings of the research study are presented in this monograph, revealing that motivational interviewing can be an effective intervention in strengthening the motivation to make health-related behavior changes of patients with cardiovascular disease and chronic joint diseases. Two main questions are addressed in this monograph: which types of health behaviors can be affected by motivational interviewing, and how important are other individual factors (such as emotional state and personality traits) to the effectiveness of motivational interviewing. Hopefully, this monograph will be useful for both researchers and health care practitioners while planning the evidence based implementation of psychological interventions in psychosocial rehabilitation settings.