Grounded theory comprises a family of research approaches designed to support the generation of a theory explaining a phenomenon experienced by a group of participants. One style of grounded theory, Classic grounded theory, is used less often than other types of grounded theory. The less frequent use of Classic grounded theory may be attributed to the limited availability of clearly articulated processes for conducting this method. Particularly important within Classic grounded theory, and not used in other forms of grounded theory, is identifying the participants' main concern. Identifying the participants' main concern is a signature feature of Classic grounded theory and is a prerequisite for ascertaining the core category and subsequent discovery of theory. In this article we provide a detailed explanation of how to identify the participants' main concern, and in so doing, we offer an exemplar to illustrate the process involved.