This article conceptualizes an attachment-based model of the student-field instructor relationship, based on empirical research concerning internal working models of attachment, which continue into adulthood and serve as templates for life-long relating. Supportive relationships within a noncritical context are salient for effective supervision; attachment theory provides a framework for developing supportive supervisory relationships and augments existing theories of supervision. Ideal and problematic supervisory relationships are presented followed by recommendations for interventions and future research. The supervisory relationship will be most successful when the field instructor is guided by attachment theory and its conceptualization of a "secure base" (Bowlby, 1988). (Contains 1 figure, 1 table and 1 footnote.)