The article examines to what extent Dutch and Spanish officials make trade-offs between process and result accountability during the design, management and adaptation of contracts for public-private partnerships. The countries' distinct administrative traditions (legalistic versus managerial-oriented, respectively) are expected to be influential. Analysing contracts, policy documents and interviews with 89 Dutch and Spanish project members, the article shows that Dutch administrators focus on outcome accountability, following the tenets of relational governance, whereas Spanish officials opt for process accountability in line with the contractual governance framework in non-clinical services, and for result accountability for clinical services in hospitals. Points for practitioners center dot Procedural and results-based accountability are not necessarily alternatives. High legalistic countries may emphasize process accountability but results-based accountability is needed to realize the potential from the private-sector operator delivering public services. center dot Long-term contracts require that the procurer first sets the results to be achieved and then work out the more suitable accountability mechanisms. center dot Results-based accountability requires competencies that are not easily found in the public sector of legalistic countries and this is key for properly giving account of the contract.