The number of women seeking medication abortion and alternative methods of self-induction is increasing rapidly around the world, particularly in contexts where abortion is highly restricted or where abortion is legally available but inaccessible, such as South Africa. Despite these trends, there is a lack of understanding of women’s experiences with informal sector abortion; furthermore, existing abortion research methods are limited in their ability to accurately measure the prevalence and behaviors of informal sector abortion. The goals of this proposed project are three-fold: 1) to understand women’s experiences with abortion outside of legal, public or private sector services; 2) to pilot a novel sampling strategy, Respondent Driven Sampling (RDS)—a previously untested method for measurement of stigmatized behaviors—among women who have had experiences with informal sector abortion in Johannesburg; and 3) to employ RDS analysis techniques to generate population-representative estimates of informal sector in the areas sampled. As the first study of its kind, results from this study have broad-reaching implications for abortion research globally as a mechanism to produce less-biased estimates of key abortion outcomes. In addition, through the proposed study we expect to better understand women’s experiences with and prevalence of informal sector abortion, and produce data that could help to improve access to quality services for women in South Africa.