The present dissertation aims to contribute to the study of consumption dissatisfaction, mainly to supplement the areas of health and markets regulated by government agency, contributing to academic studies and business actions. To do so, it sought to understand the factors involved in the formation of dissatisfaction with the management services of health actions of a Brazilian supplementary health care provider. The survey was based in a qualitative research with 20 in-depth interviews with the beneficiaries from the chosen health care provider, which have formalized complaint in the organization s own communication channels or industry regulator (ANS). From the collected data, it was possible to find five categories of analysis: consumer expectation before usage of the service, prior knowledge of the consumer, the service s aspects that influence the most on consumer dissatisfaction, the strong presence of consumers feelings on the perception of the service and the influence on post-dissatisfaction behaviors.