This study aimed to provide a reliable instrument for evaluating the physicians' communication behaviors and to find out what communication behaviors could elicit patient trust. Questionnaires were distributed to patients and they were asked to evaluate the physician's communication behaviors he/she just visited and his/her level of trust in the physician. Through factor analysis, a three-factor physician communication behavior scale with good internal consistency was provided. The three factors were respect and caring, competence and thoroughness, patience and honesty. Through correlation analysis, all the behaviors identified in the scale were significantly associated with patient trust. Physicians' behaviors related to competence and thoroughness were regarded as most important to patient trust. Privacy, eye contact and necessary tests and procedures were not considered very important. Moreover, within different gender groups and age groups, patients' opinions about what behaviors had the strongest (least) association with patient trust were a little bit different.