Unionized employees have their commitment courted by both their employer and union. They can form a commitment to both, or only one, or neither. It is difficult to predict which commitment might form. It is hypothesized that interpersonal trust and participation attitudes will explain the levels of union commitment formed by union officials. Multiple regression equations and a structural equation model were used to test these hypotheses. Interpersonal trust had a positive yet non-significant effect on union commitment. Participation attitudes had a significant, negative effect on union commitment, opposite that of the hypothesized relationship. The hypotheses are only partially supported.