Trust is an important factor in the relationship between physician and patient. Trust between physician and patient is an important factor in improving patient and physician satisfaction, but it will not materialize unless we define trust and its criteria. Since trust fulfillment is dependent on its criteria, in this study we tried to define these criteria. First, we explicated the meaning and concept of trust through review articles, then we proceeded to content analysis, and lastly, the logical conclusion was obtained. In this article we have expressed scientific opinions and extracted 23 components from the cited opinions. We concluded that trust can be analyzed from three perspectives: the perspective of patients with 5 criteria, the physicians' view with 2 criteria and the perspective of an observer of the physician-patient relationship with 9 criteria.