Transition to the first year of university is linked to steep declines in moderate-vigorous physical activity (MVPA). The purpose of this study was to investigate the effects of a targeted, theory-driven, print-based intervention on MVPA during transition to university. Volunteer participants from five Canadian universities (n=255) completed measures of MVPA at the start of their first semester at university and were randomly assigned to conditions receiving a first-year-student physical activity and action-planning brochure, Canada's Physical Activity Guide (CPAG), or a no-intervention control group. Six weeks later, a follow-up measure of MVPA was obtained as well as retrospective accounts of physical activity action-planning strategies and self-efficacy for scheduling physical activity. At the follow-up, students who received the targeted first-year student physical activity brochure reported significantly higher levels of MVPA compared to controls (p<.05) and a trend towards higher MVPA compared to the CPAG group (p=.06). However, there were no differences between groups on action planning or self-efficacy. A theory-driven and targeted print media intervention can offer low-cost and broad-reaching effects that may help students stay more active or curb declining levels of MVPA that occur during transition to university.