Originating in black feminist scholarship, intersectionality theory is emerging as a corner-stone of sociological thought. It encourages us to consider the ways in which upstream social determinants such as racism, sexism and classism form interlocking systems of oppression that shape the experiences and life chances of individuals as a consequence of their multi-dimensional social identities. Contextual forces such as sexism or racism do not operate in isolation but interact with each other in the production of health inequalities. Intersectionality is being increasingly adopted in social epidemiology because it dovetails with the domain's focus on the underlying power structures that produce inequalities (rather than inequalities simply resulting from the accumulation of independent risk factors). There is growing interest in applying intersectional approaches in health inequalities research. While theoretically rich, intersectionality has yet to be sufficiently tested in the health domain and there is a need for greater evidence and debate for how it can contribute to current population health approaches.