This thesis has emphasized the significance of company valuation as a part of the acquisition process, which is a type of business combination, as well as significance of a controlling role at various stages of planning and realization of business combinations. It has been proven that through application of different approaches and methods of acquisition valuation, insight is achieved into various aspects of the final value of a business combination. Prevailing choices in practical use and issues associated with the overall acquisition process indicate room for improvement in business practices, whereby, the role of controlling as a functional and organizational frame, is inevitable. Therefore, through role and tasks of controlling, it is possible to recognize positive and negative aspects of certain businesses and offer management impartial and objective valuation and recommendation to determine a final decision on a business combination. In the application part of the thesis, various methods were used in the valuation of Ledo PLC and analysis of deviations from the market value was performed. Nine additional companies were analysed by multiplier of comparable companies method and 2 regional acquisitions were analyzed by applying the same method. Through analysis and assessment of controlling role in business combinations and company valuation process, research was carried out on a sample of 22 companies operating in over 10 different industries, out of which 20 participated in a business combination. The results indicate that presence of controlling is important in business combinations, valuation process and in monitoring stage of post acquisition effects. In the acquistion process prevails the discounted future free cash flow (DFCFF) method. However, the multiplier methods is significantly present as well as a combination of multiple methods. Reliability of accounting information and financial statements is assessed as very high. Additionaly, audit reports which are reviewed are often used in the valution process, as well as due diligence which is carried out by internal financial analysts and external consultants.