Te Tiriti o Waitangi was negotiated between the British Crown and Indigenous Māori leaders of Aotearoa New Zealand in 1840. Māori understood the agreement as an affirmation of political authority and a guarantee of British protection of their lands and resources. The Crown understood it as a cession of sovereignty. The tension remains, though legal and political developments in the last 35 years, have established that the agreement places a mandatory obligation on the Crown to protect and promote Māori health. It also requires that Māori may exercise rangatiratanga, or responsibility and authority, in relation to health policy development and implementation. Te Tiriti is, then, an instrument against which health policy is justly and efficaciously evaluated. This paper introduces critical Tiriti analysis as such an evaluative method. Critical Tiriti analysis involves reviewing policy documents against the Preamble and the Articles of te Tiriti o Waitangi. The review process has five defined phases: (i) orientation; (ii) close reading; (iii) determination; (iv) strengthening practice and (v) Māori final word. We present a working example of critical Tiriti analysis using the New Zealand Government’s Primary Health Care Strategy published in 2001. This policy analysis found poor alignment with te Tiriti overall and the indicators of its implementation that we propose. This paper provides direction to policy makers wanting to improve Māori health outcomes and ensure Māori engagement, leadership and substantive authority in the policy process. It offers an approach to analysing policy that is simple to use and, inherently, a tool for advancing social justice.