This study attempts to contribute to a better understanding of the main constraints/ boosters for MSME growth in selected countries of the MENA region (Tunisia, Egypt, Morocco and Jordan). A multinomial logit model is used to investigate the impact of a three-fold classification of firm growth determinants (company characteristics, manager characteristics and business environment characteristics). The Database is provided by the World Bank Enterprise Surveys (MENA ES). Results give statistically robust evidence that innovative firms are more likely to grow. Therefore, the implementation of efficient and well governed systems of innovation is a priority in MENA region.