PurposeSmall and medium enterprises (SMEs) are engines of economic growth. Research indicates that the adoption of green procurement practices (GPPs) significantly influences the sustainable growth of SMEs. However, there is a lack of understanding of factors that link the adoption of GPPs with enhanced competitiveness. The purpose of this study is two-fold: first, to identify factors that affect the competitiveness of SMEs caused by adopting GPPs, and second, to test those factors whether they serve as necessary conditions in achieving that competitiveness.Design/methodology/approachA quantitative approach was used to survey 188 manufacturing SMEs in Pakistan. Cross-sectional data was collected through online questionnaires and analyzed using structural equation modelling (PLS-SEM) and necessary condition analysis (NCA).FindingsResults indicate a less pronounced direct association between the adoption of GPPs and firm competitiveness. However, this association becomes strongly positive with the mediating roles of SSB and GI. On the other hand, NCA results reveal that the adoption of GPPs, SSB and GI acts as necessary conditions for achieving firm competitiveness.Practical implicationsThis research highlights the fact that simply adopting GPPs is not sufficient to guarantee true competitiveness; a multifaceted approach is required. Moreover, it offers practical insights into effective planning of green investments leading to sustainable development.Social implicationsVarious practical measures can be adopted to manage the social outcomes of investment in the adoption of GPPs by SMEs.Originality/valueThis study relates and contributes to the natural resource-based view (NRBV) theory, the stakeholder theory and the necessity theory by developing a novel analytical framework.