T This study focuses mainly on the assessment of sustainability reporting quality(SRQ) reflecting GRI G4 sustainability reporting guideline adoption withincompanies in Indonesia. The purpose of this study is to examine (1) the extent ofGRI G4 Guideline adoption readiness; (2) the GRI related content ofsustainability reporting quality of companies in Indonesia; (3) the influence ofcorporate sustainability determinants, namely corporate reputation (CR) or alsoknown as corporate exposure (CE), competition pressure (CP), stakeholderpressure (SP), and corporate social responsibility (CSR) strategy (CSS) to GRI G4adoption readiness and SRQ; (4) the relationship between GRI G4 adoptionreadiness and SRQ.Path Analysis with Partial Least Square model was applied to test the hypotheses.Samples were taken from stand alone sustainability reports of companies inIndonesia as close as possible to population of the available sustainability reportsin 2014. In addition to the quantitative and content analysis applied to measure thelevel of SRQ and investigate the relationship between GRI adoption readiness,SRQ and their determinants, the analysis on survey questionnaires and interviewswas also conducted. A pilot study was undertaken prior to the main study as thisresearch area is considered relatively new in Indonesia.Results of this study indicate that the majority of hypotheses can be accepted andsuggest that: (1) CE, CP, SP, and CSS have significant influences on GRI G4adoption readiness and SRQ; (2) the correlation between GRI G4 guidelineadoption readiness and SRQ is negative and not significant.This study has implications by enriching the existing literatures on SRQ and itsguideline adoption study, particularly in the context of developing countries. Oneof the most important findings is the attributes of SRQ constructed that providesfresh perspectives. This study represents the first attempt to develop a newmeasurement of SRQ assessment by referring to GRI guideline principles. It alsoflourishes future studies development in sustainability reporting by examiningpotential effects of Stakeholder, Legitimacy and Institutional theories.Some efforts have been conducted to reduce the emergence of limitations dealingwith some issues such as the limited number of sustainability reports andquestionnaires, the possibility of response bias in the questionnaires, andsubjectivity in content analysis process