The purpose of this study was to examine the association between physical activity participation and stress among undergraduate students at a private East Coast Catholic and Jesuit university. Specifically, the relationship between physical activity participation and stress was investigated using secondary data collected from the 2017 American College Health Association-National College Health Assessment II (ACHANCHAII). The following research question guided the study: Is there a relationship between physical activity participation and stress among undergraduate students at a private East Coast Catholic and Jesuit university? Results found a small but significant negative relationship between moderate physical activity participation and stress and between vigorous physical activity participation and stress. Specifically, as students participated in more days of physical activity, their stress level tended to decrease. Next, students who met the ACSM moderate and moderate/vigorous combined guidelines revealed lower mean stress levels; however, the same was not true for vigorous ACSM guideline attainment alone. Finally, the study did not reveal an association between above average stress level and ACSM guideline attainment at the moderate, vigorous or moderate/vigorous combined levels. Quantitative results provided evidence-based recommendations for the integration of physical activity programs and education as an important preventative co-curricular option to combat mental health disturbances (i.e., stress) on college campuses. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]