A strategic group is defined as a set of firms within an industry pursuing a similar strategy. The strategic group concept emerged with much promise over 40 years ago. Research on strategic groups over time in a broad variety of settings has sought to clarify their theoretical and empirical properties. These research findings are gradually being translated into practical managerial guidance, so that the strategic group concept can be understood, operationalized, and used productively by managers. Two main approaches exist for identifying strategic groups—a ground-up approach, using disaggregated data, and a top-down, using cognition. Once identified, managerial insights can be derived from clarifying a strategic group’s profile. Firm membership in a group helps to uncover immediate and more distant types of competitors. Group profitability differences reveal the more rewarding and less attractive areas within an industry, as well as identify the lower-return groups from where firm exits are likely to occur. Group dynamics reflect competitive and cooperative behavior within and between groups. Several promising areas for future research on strategic groups to improve understanding and practice of strategy.