Implementation pervades strategic performance. It is a critical link between the formulation of marketing strategies and the achievement of superior organizational performance. Research conducted in this area generally has suffered from a lack of conceptual and empirical grounding. Furthermore, implementation research often ignores the mid-level managers, who are intricately involved in most implementation activities. The authors integrate a broad literature review and a grounded theory-building process to develop a model of important factors that influence the implementation of marketing strategies from a managerial perspective. They test this model in a study of mid-level marketing managers in two different organizations. The results provide insights into the nature of implementation in marketing and suggest future research opportunities.