The Rejoso business case is based on information from piloting a payment for ecosystem services (PES) scheme aimed at stimulating multi-stakeholder co-investment in restoring and maintaining good watershed functions. The business case presents the benefits of applying innovations in setting the PES pilot that enhance participation and inclusiveness of smallholder farmers in the programme, link the scientific approaches to on-theground actions and, ultimately, ensure that the programme is cost-efficient and effective in restoring and maintaining watershed functions compared to ‘business as usual’.