A widely views has it that taxable adults in Enugu state evade tax payment, thereby depriving government of revenue. For this reason, this study focused on tax evasion: causes and implication on Enugu state government revenue so as to understand the importance of taxation towards improving internally generated revenue in Enugu state to enable government of the state provide her citizens with adequate amenities without hoping on statutory allocation. In the light of this study, two specific objectives, two research questions and two hypotheses were listed, asked and tested. The study adopted survey research design with a population of 3070 and a sample size of 354. The sample size was derived statistically by using Taro Yamane statistical technique. Simple random sampling technique was adopted and questionnaire was used for data collection. The questionnaire was administered by the researcher coupled by her sister’s assistance to the respondents which the questionnaire were not collected immediately so as to elicit clear response. Hypotheses were tested using Chi-Square with the aid of statistical package for social sciences (SPSS). One of the findings shows that tax evasion has implication on Enugu state government revenue. Since tax evasion has implication on Enugu state government revenue this clearly implies that tax evasion reduces revenue generated by government of the state. The researcher concludes that tax evasion reduces revenue generated by state government which leads to debt accumulation as well as budget deficit. Hence the researcher recommended that government and other relevant agencies should promote the effort made towards preventing tax evasion in the state so as to enhance increase in government generated revenue.