Despite the centrality of sexual and reproductive health (SRH) to UN Sustainable Development Goals (SDGs), women migrant workers in Malaysia face an environment inimical to their SRH needs. Drawing on qualitative case study material, we present the first empirical application of the capability approach (CA) to explore the reproductive health needs of women migrant workers in a developing country, offering an original analysis of the capability for SRH of these women. Specifically, we explore the resources available to them; their opportunities and freedoms ("capabilities"); and factors that mediate transformation of resources into capability sets ("conversion factors"). While SRH information and health care are notionally available, women migrant workers face multiple challenges in converting resources into functionings, constraining the achievement of capability for SRH. Challenges include language barriers, personal beliefs, power relations between workers and employers and the consequences of current migration policy. We consider the scale of the challenges facing these women in securing SRH rights, the difficulties of operationalising the CA within such a setting, and the implications of our findings for the adequacy of the CA in supporting marginalised populations.