There are some factors that have been used to explain why the presence of a calling (i.e., “an approach to work that reflects the belief that one's career is a central part of a broader sense of purpose and meaning in life and is used to help others or advance the greater good in some fashion” (Duffy & Dik, 2013, p. 429) reduces work stress and its potential negative outcomes, such as absenteeism, job performance and productivity, work-related accidents and overall employee health. The effect of problem-focused coping, however, remains largely untested as a potential mediator in this relation. The present study was conducted to quantitatively test whether problem-focused coping would mediate the relation between having a calling to work and perceived work stress in zookeepers. Participants were recruited through an online survey. They responded to questionnaires regarding calling, problem-focused coping, and work stress. Using hierarchical regression analyses, it was found that problem-focused coping partially mediated the relation between presence of a calling and perceived work stress. Specifically, having the presence of a calling to work predicted greater problem-focused style of coping, which, in turn, led to lower perceived work stress. Future directions for research were discussed.