The reasons why people decide for or against seeking medical help for infertility are still far from clear. With advances in reproductive medicine, use of medically-assisted reproduction has increased over the last three decades. Over the same period, an appreciable amount of quantitative studies on the determinants of medical help-seeking for infertility has accumulated. However, to our knowledge this narrative review is the first to summarize and evaluate findings from these studies. This review includes 39 studies carried out in 11 countries, covering the period 1990–2019. We have identified five categories of determinants of help-seeking: socio-demographic variables, socio-economic factors, reproductive history, attitudes, and psychological factors. Each category consists of several variables. Considerable knowledge has accumulated on socio-economic variables, indicating that there is social inequality in access to treatments in several countries. Less is known about marital status, attitudes and psychological factors. Findings on the latter two mostly derive from two US surveys. Overall, the body of research appears heterogeneous and fragmented. Studies differ in central aspects of study design (definitions of the analysis sample and of help-seeking, type of analysis (bivariate or multivariate), set of variables included in multivariate studies) making comparisons of findings difficult. Low comparability is reinforced by country differences in the provision of treatment, legislation on access and treatment coverage. The majority of papers lack a theoretical foundation or reference to any theory. Using a theoretical framework to guide empirical research could help to overcome the problems described above. Single-country studies should include information on legal and cultural context. More studies from countries other than the US are needed as well as multi-country studies in order to develop a systematic understanding of how macro-level structures relate to decisions about medical help-seeking. This review should assist future researchers in their attempt to conduct studies on help-seeking for infertility.