This paper investigates whether firms' joint implementation of organisational innovation and training may foster their adoption of environmental innovation (EI), and if this correlation falls within Porter Hypothesis (PH) framework. We study the relationship of complementarity between strategies of High Performance Work Practices (HPWP) and Human Resource Management (HRM) when EI adoption is the firms' objective, using an original dataset on 555 Italian industrial firms regarding EI, HPWP and HRM, coherent with the last CIS2006-2008 survey. Results show that sector specificity matter. The only case in which strict complementarity is observed in organisational change concerns CO2 abatement, a relatively complex type of EI, but this is true only when the sample is restricted to more polluting (and regulated) sectors. This evidence is coherent with the Porter hypothesis: complementarity-related adoption of EI is an element of organisational change in firms that are subject to more stringent environmental regulations. Nevertheless, the fact that strict complementarity is not a diffuse factor behind the adoption of all environmental innovation indeed does not come as a surprise. At this stage in the development of green strategies, the share of eco-firms is still limited, even in advanced countries that are seeking tools for a new competitiveness. The full integration of EIs within the internal capabilities and firm's own assets is far from being reached, even in advanced and competitive industrial settings.