Purpose: This research aims to investigate which are the green purchasing practices that Portuguese manufacturing companies have been using and the relationship with company overall performance. This paper focuses on green-purchasing practices, such as green products, green suppliers, environmental collaboration with suppliers, green packaging, and reverse logistics, to ensure sustainable practices in the supply chain, and the influence of those practices on firm’s performance was investigated from the perspective of managers perception.Design/methodology/approach: A qualitative approach was adopted, based on eight case studies. Data was collected from semi-structured interviews with procurement managers from Portuguese manufacturing industry and from reports, websites and companies’ internal documentation. To analyze the impact of green purchasing practices on company overall performance a conceptual model was proposed.Findings: The results support three out of five propositions of this research, and evidence reveals that green purchasing practices improves company overall performance. Provides evidence that the implementation of those practices positively influences overall company performance, it also identifies the most frequent green purchasing practices that may help businesses in adopting environmental initiatives.Research limitations/implications: While the sample included organizations from several economic sectors, it was based on just a sample of eight case studies and the findings may not be valid in different sectors. This research focuses on green procurement from a country's perspective, which reduces the ability to generalize the findings to other countries.Practical implications: Managers might utilize the results of this study to develop and implement green purchasing practices and enhance organizations' overall performance via their adoption.Social implications: This research contributes to the current discussion in green supply chain literature.Originality/value: This study contributes to the existing body of research on the effects of implementing green purchasing practices into the procurement function.