Arguments pertaining to the size of bank capital are subject to many disputes. Since there is no satisfactory answer to this question, it may be stated that the size of a bank’s capital represents a function of the operational risks it undertakes. Ensuring credit ability of the bank causes the need to determine the standards of solvency, i.e. adequacy of capital. The following text pays attention in particular to the solvency evaluation of the banking sector in the Republic of Serbia.