Mergers and acquisitions (M&A) have become an essential business tool in a global marketplace characterised by the increasing importance of intellectual property (IP) assets. Due to modern innovative techniques and recent technological advancements, IP now forms a significant proportion of a company's assets. Compared to other industries, firms in the chemical industry constantly generate IP assets, making IP the driving force for creating value within the industry. With the significant expansion of M&A activity ongoing within the industry, IP continues to drive the industry for growth, strategic change, and consolidation. Besides the increasing M&A activity, a more complicated set of dynamics of high M&A failure rate is at work, particularly within the European Union (EU) chemical industry, where the average failure rate sits at 70-90%. Drawing on practice based theory and insights from studies on IP and its management, this study investigates the pre and post- M&A IP management practices of merged chemical firms in the EU to understand the effect of M&A on IP management practices and its implication for M&A success. Thirty-four semi-structured interviews with seven European chemical firms were conducted using a mixed-methods approach. Two face-to-face and three telephone interviews and twenty-nine written responses to the interview questionnaire. Through mainly qualitative data analysis methods of elicitation, observations, document review, and consideration of events surrounding the effect of M&A on IP management practices, the effect of M&A on IP management practices was investigated. Pre- and post- M&A intellectual property management practices of the chemical firms were identified and reviewed, following a developed intellectual property management development process (IPMDP) and an intellectual property management practice (IPMP) model. This study finds that having an intellectual property plan and model is critical to improving due diligence in M&A transactions. It finds that employing and involving IP management experts and including a communication and employee training and development strategy in M&A processes can increase the success of M&A transactions. Based on interpretivists’ objective of gaining understanding, this study contributes to a practice-based view on IP management that the most critical M&A success solution involves firms understanding their IP management practice requirements in M&A.