This book aims to analyze the characteristics of the process of strategy formation in a small advertising company throughout its existence, under the model proposed by Pettigrew (1987) for the contextual and procedural analysis of change in organizations. It is a case study, and the unit of analysis, the agency HD Comunicação, precisely in the period from 2002 to 2012. The phases and events that occurred throughout its existence were analyzed taking into account the precepts proposed by the author. The dimensions studied in the process characterization were the internal and external context, content and process. The research is qualitative, exploratory, analytical, longitudinal and retrospective. The sample is composed of six participants who are strategic management actors or who experienced, in some of the phases, each event that occurred in the company. Data collection was based on semi-structured interviews and documentary research. The agency and its trajectory throughout its existence was contextualized. The formation of strategies, in its events, was modified by the external context, available resources and previous experiences.