Worldwide interest in teaching medical professionalism has increased drastically over the past two decades and is recognized as an important core competency. It is also essential in pharmacy education. However, there is no single definition of medical professionalism owing to its multifaceted nature, leading to difficulty in understanding it. The foundational concept of professionalism are the social contract and accountability, which describe the relationship between the profession and the society which it serves. Profession must understand expectations from the society, which is trustworthy, assures competence, and devoted to the public good for the contract based on their mutual trust. In "teaching," three basic educational actions ("setting expectations," "providing experiences," and "evaluating outcomes") are required. There are two learning goals of professionalism education: the minimum goal of not doing unprofessional acts and the aspirational goal of pursuing a higher level of interiorized professionalism which leads to the professional identity formation. The true professionals are "reflective practitioners," who have the ability to manage ambiguous problems using their interiorized professionalism in complicated situations. Therefore, reflection is one of the central concepts of professionalism education. The Professionalism Mini-Evaluation Exercise (P-MEX), an observational tool to evaluate medical professionalism, has some favorable aspects; the Japanese version is available and is a guide to specific actions for professionalism through its items, although some cautions must be exercised when using it. Considering that teaching professionalism includes not only formal but informal and hidden curricula, all of the staff in the educational environments should consider professionalism education by understanding professionalism.