Environmental flows (E flows) are now a standard part of sustainable water management globally but are only rarely implemented. One reason may be insufficient engagement of stakeholders and their priority outcomes in the E flow-setting process. A recent environmental flow assessment (EFA) in the Kilombero basin of the Rufiji River in Tanzania concentrated on a broad-based investigation of stakeholders’ use and perceptions of the ecosystem services provided by the river. The EFA process generally followed the Building Block Methodology but with an enhanced engagement of stakeholders. Engagement began with the involvement of institutional stakeholders to explain the purpose of the EFA and to elicit their priority outcomes. Extensive interactions with direct-use stakeholders followed to investigate their uses of and priorities for the rivers. Results were used by the EFA specialist team in choosing flow indicators and defining measurable environmental objectives. The specialists then met to reach a consensus of the flow requirements. The EFA results were lastly reported back to stakeholders. During the Kilombero EFA we learned that stakeholders at all levels have a good awareness of the natural services provided by a healthy river and can contribute to the setting of environmental objectives for the rivers and floodplain. These can be factored into the biophysical assessments of river flows required to maintain habitats, processes, water quality and biodiversity. It is therefore important to allocate significant resources to stakeholder engagement. It now remains to be seen if enhanced stakeholder engagement, including the increased understanding and capacity built among all stakeholders, will increase support for the implementation of the recommended flows.