Outdoor leaders function in naturalistic decision-making contexts and may be influenced by personal, social, and environmental factors in making critical decisions in the field. The experience level of the outdoor instructor is posited as a critical variable in the development of his/her decision-making and overall judgment. This research measures the effect that experience has on medical decision-making in outdoor leaders. It investigates two research questions: (a) Do outdoor leaders of varied experience levels differ in their perception of factors in the decision-making environment?; and (b) Do outdoor leaders with different experience levels vary significantly in their judgments? Decision-making was measured utilizing factorial survey vignettes in a hierarchical linear model. Experience was assessed using experience use history methodology (OLEUH). The sample includes Outward Bound staff (N=103). Data were collected in June 2002. Significant variance was present in both the perceptual threshold and judgment processes for the group cohesion predictor variable. Discussion and implications for future modeling naturalistic decision-making processes are included.