Few empirical data exist to demonstrate the efficacy of marriage and family therapy (MFT) training and supervision. In order to lay the foundation for a comprehensive model of MFT supervision and faciliate supervisory precess research, variables improtant to the outcome of MFT supervision were identified. A panel of AAMFT Approved Supervisors generated 771 variables thougth to be essential to superisory outcome and rate 398 of these variables as very improtant to the outcome of MFT supervision. The variables were collapsed into five categories and further divided into 37 conceptual clusters. The existing superisory literature tht supports the results of the study and implications of the study are discussed.