The valuation of a company is a complex process and requires comprehensive knowledge. The decisions made at each stage have consequences for the next step. The first fundamental stage is to choose the standard of value that the valuer wants to determine. Only then is the appropriate valuation method selected. One of the further factors influencing the outcome of the valuation process is the cost of equity, which takes into account important parameters of the company's operation. It is the cost of equity that causes the most controversy and dilemmas. The research problem analyzed in the article is a way of calculating the cost of equity in enterprise valuation. The example of a specific valuation indicates that the cost of capital cannot be a parameter (data item) covering all risks, but only those that cannot be programmed in cash flows. In the course of research works, the valuation of enterprise B organized in the form of a general partnership as of 29.08.2014 in connection with its contribution by the shareholders to the joint-stock company A as an in-kind contribution increasing the capital was performed. Due to the fact that there is a minority shareholder in joint-stock company A, there is a dilemma of choosing the right value and valuation method and the method of calculating the cost of equity. Neither the literature on the subject in this respect, nor the parties to the transaction, indicate a clear solution, especially as regards the value of the cost of equity.