Through the lens of the contextual intelligence theory, this article utilises previous empirical research studies as a base to support the application of professional discretion practices of public-school principals. The study focused in particular on the factors that influence or limit their use of professional discretion in their daily tasks. A mixed-methods study was conducted in which quantitative survey data were used to inform the questions that were asked to participants during semi-structured interviews. The findings suggest that public-school principals are susceptible to both internal and external factors that could limit or influence the application of their professional discretion. Even though public-school principals within a particular school district operate under the same set of policies, it is evident that some principals are more inclined to apply professional discretion than others.