The aim of this study is to identify the influence of the institutional environment on the trend of Third Sector Organizations to evaluate their activities. The organizations analyzed were operating in Belo Horizonte in the State of Minas Gerais in 2006. The rationale underlying these influences, directing both institutional agents and organizations, are discussed. The paper points out that, in the search for legitimacy and social acceptance, these organizations are under pressure to conform their structures according to agents which operate with a clear instrumental rationality. These influences, classified according to each agent, emerge from the statistical tests. They demonstrate that, in relation to the legal status, organizations structured as foundations tend to evaluate their services more than those structured as associations. Titles and certifications do not influence the evaluation of services. The influences of funders and of public policy committees appeared to be considerable. Therefore, the organization's success seemed to be more tied to the factors that satisfy most of the institutional forces and pressures which are increasingly being demanded for higher levels of organization performance.
Third sector; Performance evaluation; Rationality; Institutional theory