For over 50 years, the Stuttgart method has been used to determine the value of non-listed companies for inheritance, gift, and wealth tax purposes. Following the ruling of the Federal Constitutional Court on November 7, 2006, the legislator is required to reform inheritance tax and ensure a market-oriented valuation of business assets. Based on extensive empirical analysis, Jens Müller explores how much the valuation by the Stuttgart method deviates from market values and in which cases an acceptable approximation of the market value is achieved. In practice, the multiplier method is often used to value non-listed companies. The author examines how this method can also be suitable for tax purposes and outlines the estimation errors that can be expected.