In an effort to fight corruption, the Indonesian government has put eprocurement as one of the strategic programs among the seven flagships of the National Information Technology Council (DETIKNAS). One very successful developer of an e-procurement system is the Public Procurement Policy Institution, or Lembaga Kebijakan Pengadaan Barang/Jasa Pemerintah (LKPP), with 731 government agencies and 333,452 suppliers accessing LKPP's system. This study was conducted to analyse the determinants of an e-procurement system's success as well as its impact on perceived transparency from the supplier's perspective. This study answers both questions by applying a covariance-based structural equation modelling approach to analyse the survey data of 157 respondents. This study finds that only system quality, service quality, regulation, trust, user satisfaction, and perceived benefits determine an e-procurement system's success. However, only trust in an e-procurement system predominantly affects perceived transparency. © 2018 Inderscience Enterprises Ltd.