This essays focuses on analyzing Embratel (a large telecommunications company) cultural management, in the post privatization period, when organizational values got aligned with the values of the finance subculture, that emerged as the dominant subculture, and identify its impact in organizational performance. The organization, confronting with an hostile environment, faced a crisis in its results, that drove to a reformulation in its strategic objectives, that gained a financial focus. Through qualitative analyses, a case study was conducted relating the emergence of subcultures, culture change and performance. The research was based on a documental analysis and semi-structured interviews. The cultural agreement process and its impacts in financial performance were investigated. The conclusion of this study reinforces the hypothesis in the organization theory that indicates a strong correlation between the emergence of dominant subcultures, periods of external and internal turbulence, changes in the organization structure, showing the key influence of some variables in the cultural changing management process with focus on performance, such as: power structure, training, communication, reward, selection and evaluation systems and decision process.