Merger and acquisition operations are encumbered with a great risk of failure. This is due to the fact that the operations are complex, multistage, and often unique. It results in profound changes in numerous areas of functioning of enterprises being merged, and affects the external environment. Initiation and realization of the process is most complex and costly economic operation, necessitating different, often unique competence. Moreover, a merger operation requires support from many parties. Taking up such a transaction we must take into account, in particular, a risk of failure and the necessity to write-off the costs incurred; and in case of a success - a potential failure to achieve tasks assumed. A merger operation is successful when the value of a merged enterprise or a capital group (i.e. a purchaser and an acquired company) increases in comparison to the value of each separate company prior to merger. The increase in value is the result of the synergy effect, inaccessible to units that used to operate separately, and available after the merger. For an efficient realization of any project good preparation and efficient management are crucial. An element of promptness accompanied by due diligence are important. This means a smooth management of the merger process, including recruitment of appropriate staff, work planning, flexibility of acting, efficient communication system, and high-quality analytical system. A prerequisite of all other actions is an appropriate decision on the merger with another enterprise. Further stages consist in actions taken up with an aim to find a candidate to be merged. A purchaser starts from an evaluation of its own market and financial condition, and necessary development directions. In the course of a preliminary analysis potential candidate for the merger is identified. Subsequent analyses aim at identifying, as comprehensively and thoroughly as possible, potential advantages to be obtained after the merger. Then, following the analysis of the candidate, a detailed verification of data is performed. This is made in the course of so-called "due diligence" or investment audit process. The analysis should end up with conclusions pointing at major risks and opportunities related to the operation. The analysis should allow for a full understanding of the activities performed by the candidate enterprise. The analysis is concluded with strengths and weaknesses of the enterprise, and opportunities and threats it faces. Quantification of such factors provides for a development of financial prognosis to evaluate merger effects, make a valuation, and plan the operation's structure. Within the framework of the prepared structure the following components are determined: the form of payment and the form of financing in the context of repayment capability and tax issues. Negotiations with representatives of the enterprise to be merged account for most important and complicated part of the process. In the course of negotiations strong discipline and character should be exhibited. Transactions made by force are not recommended. In case the other party expects a price exceeding maximum price arising from the evaluation, the transaction should be quit. Enterprise integration is a key element providing for the success of the venture. One of major threats related to the integration is that, in contrast to the transaction itself, integration is not that impressive - effects can be seen after some time and are difficult to a be explicitly assessed. It is extremely important that the process is subject to an ongoing monitoring by the top management in order to signal priorities of actions to performers and provide for support in case inevitable problems occur. At the same time one should be aware of the burden arising from the integration and its impact on the business activity. A merger is successful only when the newly created structure gains its new quality, higher efficiency and creativity are achieved, and the created value is going up.