This research is done at PT Mitra Kharisma Perkasa Medan. The company is engaged in sales of chemical products. The objective of this study is to know the Article 21-Income Tax compliance in PT Mitra Kharisma Perkasa Medan after conducting tax review of Article 21-Income Tax. The methods used by the writer in this research is qualitative descriptive method. The research will tax review on Article 21 Income Tax in year 2017. Based on research result, conclusion of this research is that the implementation of tax review on Article 21 Income Tax in enhancing the tax compliance in PT Mitra Kharisma Perkasa Medan. It can be seen that there is underpaid of Article 21 – Income Tax because some of employee’s income isn’t included as taxable object in Article 21 – Income Tax calculation. The calculation of the Article 21 – Income Tax for the permanent employees who have not been conducted according to the Tax Provision. The writer finds out that the company conducts manipulation of the employees’ basic salaries, bonus and new year allowances which caused the Article 21 – Income Tax becomes lower. With the implementing the tax review, the company can use the result to improve the calculation, reporting and payment of Article 21 Income Tax of each permanent employee according to the Income Tax Law. It will improve and increase the company’s tax compliance in order to avoid the tax sanction from government. Based on tax review result, there is underpaid tax of Article 21 Income Tax in amount of Rp 27,970,000.-. The company doesn’t include some of employee’s income as taxable object of Article 21 Income Tax. There is an inaccurate of calculation of Article 21 Income Tax done by the company’s employee.