The crisis situation that arose in Russia in December 2014, worsened financial standing of many companies, the number of transactions of M&As increased 5 times in comparison to the last year’s number of transactions (according to the data of the Federal Antimonopoly Service). Taking into account the recent developments on the market and based on the many years’ work experience in M&A projects, the author notes the main reason of the transactions’ failure  insufficient elaboration of the personnel management strategy.The author of the article discloses the specifics of the personnel management, points out the key tasks of human resource management in M&A projects, positive and negative outcomes for various types of transactions. To comprehend the process of the appraisal of the effect of changes on personnel the author has performed a research using an M&A project. Through the example of a real transaction of company acquisition, the author demonstrates methods for evaluating the socio-psychological climate and studies the employees’ motivation in two companies. The author in this work also gives recommendations to the management regarding the personnel management for M&A projects.