The emergence of environmental or green issues in global supply chains has made it an essential practice to measure the performance of organisations of not only from their financial and management perspectives but also their environmental performance, particularly logistics service providers (LSPs) as service providers. There has been little work done during last two decades linking the three topics of green service quality (GSQ), logistics service quality (LSQ), and the Thai government’s logistics performance index (TLPI) for the logistics sector. The objective of this thesis was to investigate issues pertaining to GSQ and LSQ, and their impact on the TLPI for logistics providers in Thailand. Based on an extensive literature review, three research questions were proposed for this thesis to address gaps in the body of knowledge. GSQ is a new area of theory development and few research studies have focussed on the on the integration of both green and logistics service quality. The study used a rigorous three-phase methodological framework originally developed for the marketing discipline for item and scale development and applied more recently to logistics research. A mixed method approach used semi-structured interviews in Phase One, in conjunction with the literature, to generate and develop variables of GSQ and LSQ. These variables were tested in a Phase Two empirical study of Thai LSPs and their customers using a questionnaire survey. Finally, in Phase Three structured interviews were conducted to verify and validate the overall results. The findings indicate that LSQ has a positive and significant effect on TLPI, and that effect is more pronounced when GSQ measures are included. Such measures indirectly affect TLPI through LSQ. The findings also propose a final set of twenty-eight GSQ and LSQ variables of importance to LSP performance as perceived by Thai LSPs and their customers, and are related generally to green safety, regulations and collaboration; time and services; order service quality; and order procedures competencies. In light of this study, Thai LSPs should consider introducing GSQ as part of their business and the Thai government might include GSQ measures as part of its TLPI.