This study aims to analyze the main criteria involved in the process of selection and prioritization of projects portfolio in Brazilian companies and compare them to those found in the project management literature trying to identify gaps between theory and practice. The theoretical framework adopted encompasses four aspects: characteristics of projects; motivation for projects; value of projects and business areas for companies. The field research adopts the multiple case study method that was carried out in different sectors: financial institutions, manufacturers, public companies and the government. The results show that the main criteria used by the six companies were the following: complexity, risk, technical feasibility, project performance, and stakeholder satisfaction. Furthermore, only the stakeholder satisfaction criterion was adopted by all companies.