The development of a country, as well as the sustainability of its fiscal policies, and its impact on social and economic policies, depend mainly on its tax system. Tax revenues allow for financing the expenses of state administration and the provision of public goods and services. The general objective of this research is to determine the relationship between tax reforms and tax evasion in Ecuador. Through a systematic literature review and a survey validated by experts, it is determined that among the most frequent causes for tax evasion are: ignorance or legal complexity at 38%, followed by the existence of mild legislation for non-compliance at 23%, Government Distrust with 18%, Inflation and Tax Pressure with 12%, and determining 9% for the Existence of an informal economy, permanent regularization regimes, and taxpayer behavior. Concluding that there is a direct relationship between tax reforms and tax evasion, being the most frequent cause of tax evasion