Most analyses of the impact of heterogeneous environmental policy stringency on the location of industrial firms have considered the relocation of entire activities – the well-known pollution haven hypothesis. Yet international enterprises may decide to only offshore a subset of their production chain – the so-called pollution offshoring hypothesis (POH). We introduce a simple empirical approach to test the POH combining a comprehensive industrial mergers and acquisitions dataset, a measure of sectoral linkages based on input-output tables and an index score of environmental policy stringency. Our results confirm the impact of relative environmental policy stringency on firms’ decisions to engage in cross-country M&As. Our findings also indicate that environmental taxation have a stronger impact on international investment decisions than standards-based policies. Further, we find that transactions involving a target firm operating in a sector upstream of the acquirer are more sensitive to environmental policy stringency, especially when that sector is highly pollution-intensive. This empirical evidence is consistent with the pollution offshoring hypothesis.