MSMEs are a key component for the economic and social development of countries, in Mexico they generate approximately 70% of jobs and contribute around 35% of GDP. There is great empirical evidence that shows that the lack of financing affects the economic growth of companies. Microenterprises are those that face the most external financing restrictions and indicate that high interest rates are their main limitation for not accessing external financing, therefore, they are the most affected in their economic growth. The objective of this research is to carry out a systemic review of the context of external financing of MSMEs in Mexico. The results infer that it is urgent to implement adequate public policies to strengthen the financial system and facilitate access to external financing under the best conditions for MSMEs to improve their competitiveness and economic growth.