Several culture theories, which explain the formation, embedment, and propagation of organisational culture, suggest that certain organisational culture practices of an executing organisation may enable sustainable outcomes in project manufacturing. However, practices that support sustainability may not support project delivery, and vice versa. We explore the effects of organisational culture practices and structural complexity on the ability of manufacturing projects to optimise both sustainability and project delivery. We use data envelopment analysis (DEA) to calculate a sustainability-delivery quotienta measure of each organisation's ability to optimise both sustainability and project delivery outcomesfor 186 projects conducted in the UK. By conducting generalised linear modelling and censored regression of the sustainability-delivery quotient, we estimate the effects of the GLOBE organisational culture dimensions, principal components of culture dimensions, and project structural complexity indicators. Results indicate a noteworthy gap between the delivery of projects and their sustainability performance, which is worse. Both institutional and in-group collectivism may support the optimisation of each. However, neither the principal components of culture dimensions nor structural complexity indicators are likely to be significant. We discuss the managerial implications.