Start-ups differ from established companies in terms of enterprise size, business model and the markets in which they operate. In their first years of operation, start-ups are characterized by above-average growth rates in sales or earnings. Such growth rates often cant be achieved without external funding, since start-ups do not have enough capital resources of their own. This is why the entry of investors is crucial. Business valuations are an important part of such external investments. However, a single round of early financing is usually not sufficient: many different rounds of financing over a start-ups life are necessary to ensure the companys long-term financial viability. Recognized evaluation methods, however, are designed for established businesses and are not necessarily suitable for start-ups. In this thesis, generally accepted methods for valuing companies are reviewed for their ability and suitability to evaluate start-ups. The aim of this thesis is to specify which method should be used for start-up valuation in which stage of a start-ups life. The first phase examines if a certain evaluation method can technically be used based upon the available data base. The second phase ensures that any technically feasible evaluation methods take into account the characteristics of the start-up in the company value. The third and final phase focuses on the practicality of the respective methods. The thesis finds that the older and the more established a start-up becomes the more extensive and more exact valuation methods can be used. In their early lives, start-ups can be valued using methods incorporating mainly individual assumptions and proxies for company values. The more mature a start-up becomes, the easier it is to use discounted cash flow methods to obtain a more exact company value. However, in practice, it is common to use more than one valuation method, especially to determine the plausibility of the calculated company values.