Based on experiences from patent transactions, potential buyers or licensors mostly see their return on investment in relation to the potential value the patents can generate. Their valuations take risks into account, such as infringement, design around and validity, as well as competing solutions, revenues, growth and expected duration of the product. If there is a likelihood that an actual or future product could be covered by a patent, this is also reflected in the value. Since the value of a patent as written on the patent owner’s balance sheet is normally based on the cost of obtaining the rights, the patent owner and the buyer will often have very different valuations. The methodology for patent valuation in this paper is based on a real case, which takes technical, legal and economic aspects into account. Both the patent owner and the buyer’s perspectives are reviewed.