Temp-to-permanent employees are temporary workers who have the opportunity to become permanent employees after a specific amount of time (e.g., generally after a 3- to 12-month period of trial work). The authors predicted that temporary worker individual differences, self-monitoring, tolerance for ambiguity, and role adjustment are related to temporary worker physiological stress and to whether temporary employees are offered permanent employment. Longitudinal data collection (pre- and postentry) resulted in data from 136 temp-to-permanent employees. Tolerance for ambiguity and role adjustment were found to be related to temporary worker stress and selection success. Self-monitoring was related to selection success for workers in an extended probationary period. These results suggest the need for further exploration and application of models of stress in understanding factors related to temporary worker success.