Changing behavior to improve health has become a public health issue. Motivational interviewing (MI) is a scientifically proven relational approach derived from Rogerian psychology. Its aim is to increase patients’ motivation to undertake a change that will benefit their health. MI has proven its effectiveness in a wide range of fields, including addiction, chronic illness, prison, education, and sports performance. Its practice requires an expertise that is itself initiated by specific training. MI has many similarities with therapeutic patient education (TPE), not only in its theoretical foundations but also in its practice. Empathy, empowerment, a positive outlook on patients’ skills and future, shared hope... belong to both MI and TPE. Thus, MI and TPE are complementary and, when practiced together, can improve the effectiveness of TPE programs, notably by increasing patients’ motivation to commit to and remain in these programs. Joint training courses in MI and TPE should be offered to caregivers, to ensure that patients’ difficulties are dealt with as effectively as possible.