Attrition is a significant problem in worksite weight loss interventions, and differences in participants' motivational levels have been hypothesized to account for this high attrition rate. The present study examined characteristics of participants who completed a worksite weight loss program compared to those who dropped out, using a step-wise discriminant function analysis. The results indicate that a combination of motivational characteristics, expectations, and change in weight just prior to treatment significantly discriminated drop-outs from completers. The results of this investigation are discussed with respect to implications for developing cost-effective worksite treatment protocols and directions for future research.