Purpose -Lack of competition in procurement processes may affect the sustainable procurement due to overpriced and low quality infrastructure. The purpose of this paper is to investigate the current practices in Malaysian PPP in handling unsolicited proposal within PPP and to suggest ways in which the practices can be improved to achieve sustainability.Design/methodology/approach -Case study was conducted within which 13 semistructured interviews were carried out with different groups: the policymakers, the practitioners and the experts. The study also scrutinised published guidelines and relevant regulations used by in management of unsolicited proposal in Malaysian PPP.Findings -The government of Malaysia welcomes unsolicited proposal from the private sector, even though it does not publish any established mechanisms to handle such proposals.Lack of competition in unsolicited proposal is a major concern in achieving sustainable goals of procurement. This could be addressed by introducing a competitive element to unsolicited proposal, Originality/value -There is limited study and reports on the implementation of unsolicited proposal by the Malaysian government. Besides adding to the literature, this paper reveals the management of unsolicited proposal. Most importantly, it is useful in assisting potential Malaysian PPP stakeholders and investors in what to expect, based on findings from the actual practice.