The aim of this paper is to explore the most common challenges, difficulties, common myths and problems that both Total Quality Management and Six Sigma met in the service organization and the way they had been adopted and implemented. Expected scientific results will suggest that just like any other concept, the extent to which Total Quality Management and Six Sigma will be successful in a service organization depends on both the initial impact and their importance as perceived by members of each service organization.Conclusions will highlight that although there is no single formula that guarantees success of Total Quality Management or Six Sigma implementation, in practice there are a variety of tactics for implementation. All these tactics of implementation involve the existence of an operational plan for identifying activities that must be met in order to achieve the intended results.