This study concerns the relationship between the information technology (IT) project performance and the project management maturity of an organization. The research was developed from a survey of 185 respondents during 2010. Project performance was evaluated using the two first dimensions proposed by Shenhar et al (2001) – project efficiency and impact on the customer. Project management maturity was evaluated using the formalization level of project management processes described in PMBoK. Data were analyzed by statistical methods (factorial analysis, Cronbach´s alpha, cluster analysis and bivariate analysis) and showed that (i) organizations with superior maturity present superior performance in their projects and (ii) different maturity dimensions have distinct impacts on IT projects performance.