The valuation of a small or medium-sized enterprise through subjective methods, may not exclude a correct contextualisation of the data forming the information base of the estimate. “Contextualisation” refers to the general overview of all those elements that allow a proper definition of the enterprise’s background. All of this serves in the analysis for the correct data necessary for the determination of values such as the economic and financial flows to discount, the timeframe of analysis and the discount rate. Without a correct contextualisation, it is not possible to reach a correct measurement of the company value in accordance with the studies on the “theory of value”. After observing that “contextualisation” has not been widely studied till now for the theory of value, the present work analyses the incidence on the measurement of the company value, showing with an empirical case the different results that may be reached on the basis of the contextualisation of data. Hence, a correct “contextualisation” is crucial for the proper valuation of a company. Academic researches should take more carefully into consideration, this aspect concerning the valuation of a company and in particular, define more accurately the implementing rules in the assessment methods.