Gun jumping is a term which describes the premature realization of a merger before obtaining a merger clearance from the relevant competition authorities. In the last years, the European Commission and national competition authorities have demonstrated an increased interest in investigating and punishing gun jumping cases. Recognizing this interest and the need for practical guidance, the article first gives an overview of gun-jumping evolution through case law. It then points to different merger filing thresholds in the region, and implications they could have for gun-jumping issues, to show that despite the commercial and historical common ground in the region, merger filing thresholds do differ significantly between the countries, in a way which requires a cautious and sometimes challenging structuring of M&A activities with regional reach. Based upon an overview of individual gunjumping cases in the region, but taking into account the EU precedents, the article provides recommendations how to avoid gun-jumping risks.