Profit tax is a form of taxation that countries in the world began to introduce into their tax systems after the Second World War. In many countries around the world, profit tax is called corporate income tax. Profit tax belongs to direct taxes that the taxpayer pays himself on the realized profit. Income tax payers are legal entities, and they can also be natural persons if they meet the conditions prescribed by the Income Tax Act. The tax base of the income tax is the profit, which is determined as the difference between income and expenses before taxation, and which for the taxpayer can be increased or decreased according to the provisions of the Law on Income Tax. In the Republic of Croatia, profit tax is calculated at the rate of 10% and 18%. Although the profit tax is not the factor that contributes to the largest filling of the state budget, profit taxation has an important role in the tax system of the Republic of Croatia. The profit tax has a strong influence on the economic climate in the country, because the high tax rates attract foreign capital to the country, increase employment in society and affect the business competitiveness of the country.