The claim that mixed methods is the third methodological movement of the twentieth century could have unexpected consequences for the future of research in the social sciences and health disciplines. Implied is a belief that the mixing of qualitative and quantitative methods will produce the ‘best of both worlds’. This assumption, combined with inherent promises of inclusiveness, takes on a reality and certainty in research findings that serves well the powerful nexus of economic restraint and evidence-based practice. I argue that the use of the terms ‘qualitative’ and ‘quantitative’ as normative descriptors reinforces their binary positioning, effectively marginalising the methodological diversity within them. Ideologically, mixed methods covers for the continuing hegemony of positivism, albeit in its more moderate, post positivist form. If naively interpreted, mixed methods could become the preferred approach in the teaching and doing of research. Rather than the promotion of more co-operative and complex designs for increasingly complex social and health issues, economic and administrative pressures may lead to demands for the ‘quick fix’ that mixed methods appears to offer.