Traditional public–private partnership (PPP) still adopts a paper-centric contracting system, which is susceptible to data and information manipulation with the associated lack of trust and transparency. These lead to unstable and confrontational relationships between the private and public sectors in delivering infrastructure projects, failures, termination, and/or cancellation of PPP contracts. Blockchain-enabled smart contracts (BSC) possess unique characteristics with the potential to strengthen stakeholders’ relationships and mitigate PPP failures. Studies on smart contract adoption in PPP are still growing, and institutional theory is yet to be adopted in the literature to examine the determinants of BSC adoption in PPP. This study leverages institutional isomorphism to assess the potential determinants of BSC adoption in infrastructure PPP. Ten institutional isomorphic forces were identified from the literature and grouped under coercive, mimetic, and normative pressures. Ninety-six questionnaire data were gathered from experienced PPP experts across countries using purposive and snowball sampling techniques. The relative important index (RII) and Spearman correlation (rho) analysis were used to analyse the gathered data, having a reliability index of 0.903. It was found that institutional isomorphic forces can strongly and significantly influence the intention to adopt BSC in PPP projects and that coercive pressure (rho = 0.888; sig. = 0.000) has the most significant influence, followed by normative pressures (rho = 0.825, sig. = 0.000) and mimetic pressure (rho = 0.822, sig. = 0.000). This study adds to the scarce literature on blockchain and smart contract adoption in PPP. This study advocates for digitalising PPP contracts for sustainable infrastructure delivery to the public.