Developments on traditional Aboriginal territory in Canada often require environmental assessments (EAs) to predict potential environmental and social impacts. Impacts considered during the Canadian government’s (Crown) consultation process (between the Crown, Aboriginals and proponents), is known as the Duty to Consult (DtC). The DtC is a legal requirement under the Constitution Act, 1982 and case law, which provides opportunities for Aboriginal rights and interests to be protected by identifying and mitigating impacts. Scope of consultation depends on the strength of Aboriginal claim and level of adverse impacts. However, in Canada, there is a lack of DtC guidelines. Whilst a lack of guidelines offers flexibility, it also presents many implementation challenges. Current DtC practices often result in proponent withdrawal, delays, protests, conflict and creates risks to project development. This paper assesses application of DtC criteria (established in EA literature), and compares them against three recent case studies across Canada. Although results show some inadequate practices, there are examples of effective DtC criteria which help reduce impacts to Aboriginal rights and land. Recommendations to improve the DtC process that benefit all stakeholders includes: increased Crown guidance to proponents; acknowledging benefits of Free, Prior, Informed Consent; increased utilization of measures outlined in EA legislation including extensions and suspensions; and stronger, earlier consultation legislation in federal and provincial EA guidelines. The above recommendations seek to reveal that more effective consultations are those which prioritize relationship building, consensus seeking and are responsive to each First Nations circumstances. Although qualitative, this study provides evidence based criteria for effective Aboriginal consultation approaches within the Canadian EA process.