In order to improve the performance of its activities, along years the organizations have been influenced by different quality boardings. Six Sigma has been being the quality boarding more commented in the lasts times and applied in an increasing number of companies, initially industrial and, more recently, in services companies. This work aims to reduce an existing lacuna between Six Sigma practice in organizations and the academic studies development about the theme in Brazil, through identification and analysis of the aspects that facilitate and complicate the implementation of this strategy in services companies. Telemar Group was selected as case study because it is a representative company in the national scenery and because have past, in the lasts years, by the implementation process of a Six Sigma program. To reach the proposed goals, the study based in the literature on quality and Six Sigma, as well as in the literature on change management. The research involved interviews with organization different hierarchical levels employees and consultants. The obtained results allowed the construction of a reference conceptual frame for the companies that intend to adopt the referred quality boarding and for future researches development, once they proved the influence of the aspects pointed as critical by the literature and added other aspects brought by the change management perspective as well as by the investigated organization particularities. Among those aspects, the short term results culture, the constant change environment, power and politics in the organization, high turnover level and others were highlighted.