This study identified and compared characteristics of 'best' and 'worst' clinical teachers as perceived by university nursing faculty and students. The Nursing Clinical Teacher Effectiveness Inventory (NCTEI) was distributed to 201 volunteer subjects. This survey instrument, developed by the authors, contains 48 clinical teacher characteristics grouped into five categories. Each participant was asked to rate, using the NCTEI, the 'best' and them the 'worst' clinical teacher from past observations. Results showed both groups perceived that being a good role model was the highest rated characteristic for 'best' teachers and the 'lowest' rated characteristic for 'worst' teachers. Faculty and students' perceptions were fairly similar as to highest rated characteristics of 'best' clinical teachers. Less agreement was noted about the characteristics of 'worst' clinical teachers. When categories of clinical teacher characteristics were compared, there were significant differences between the ratings of faculty and students for 'best' clinical teachers, but none for 'worst' clinical teachers.