The article tackles the issue of the impact of inflation and of the income tax on actual opportunities for companies’ capital investment financing with funds derived from depreciation and referred to as depreciation assets. Given the lack of indexation of the basis for depreciation allowances considered to be tax costs, under conditions of inflation tax regulations actually bring about a hidden form of taxation levied on companies’ assets. Therefore, if a company wants to maintain the real value of fixed capital assets it must compensate for shortage of depreciation assets by making use of profit available for distribution or by incurring liabilities. Results of empirical research allow to conclude that depreciation is seen by Polish companies as the major source of financing their investment activities. Inflation poses a major barrier to investment financing with depreciation assets. Consequently, companies compensate for depreciation assets shortage with net profit and reduce the level of their investment.