This paper examines factors that promote and diminish teacher trust in the instructional supervision process. Trust--key to the supervisor's success in helping teachers change behaviors--is correlated with such factors as confidentiality, approach to dealing with complaints, and the development of collaboration and participation in supervisory processes. Trust is low when a supervisor takes a teacher's confidential expressions of need and makes it reflect negatively on her evaluation. Supervisors who stress authority and identification of weaknesses build less trust than those who emphasize collegiality, productive diversity, and strengths. A study of 150 teachers in seven Kansas school districts identified supervisor practices that either enhanced or diminished trust; these practices include orientation, tone, feedback, listening skills, and support. A staff development program that elicits teachers' responses to favorable and unfavorable experiences with supervision can provide supervisors with positive notions about change, and 12 steps for building such a program are described. Supervisors develop a caring interpersonal relationship with teachers through showing consideration, appreciation, and respect, and by giving appropriate positive feedback. Areas of competence that enhance teacher trust include honest discussion of assessment goals and sharing knowledge about factors that positively influence student achievement. Relationships of trust evolve through time and effort and useful feedback from supervisors enables teachers to improve the quality of their decision making. Eleven references are appended. (CJH)