Purpose: The purpose of this paper is to assess the effects of scenario planning on participant mental model styles. Design/methodology/approach: The scenario planning literature is consistent with claims that scenario planning can change individual mental models. These claims are supported by anecdotal evidence and stories from the practical application of scenario planning. This research study documents the responses of 129 participants from 10 organizations using the mental model style survey as a pretest and posttest, with scenario planning as the intervention. Paired samples t-tests were performed between participant pretest and posttest, to test hypotheses on all five factors of the mental model style survey. Findings: Results provide evidence that scenario planning can change individual mental model styles. More specifically, results show that scenario planning promotes efficiency, social, and systems mental model styles, with moderate effect sizes. Research limitations/implications: The implications of this research include contribution to the growing body of quantitative studies attempting to document the impact scenario planning has on participants. Implications for future research include the use of control groups to isolate effects of the scenario planning intervention. Originality/value: The study documents one of the largest sample sizes to date in scenario planning research and makes a clear contribution in clarifying significant changes in mental model styles from pretest to posttest. (Contains 1 table and 2 figures.)