Aim To explore the problems involved in conducting research with populations that are hidden or hard to reach, and to suggest strategies to recruit participants.

Background Conducting research with populations that are hidden or hard to reach can pose problems. Recruitment is, by definition, difficult and it is impossible to determine if participants are representative of these populations. Nevertheless, it is important to extend research strategies to include such groups, particularly when developing targeted services.

Data sources This methodological paper draws on a research study undertaken as part of the author’s doctoral studies, in which seven men aged 16-20 years old took part in semi-structured interviews.

Discussion Several factors make research with populations that are hidden and hard to reach difficult, yet information from such populations is essential in identifying strategies that address the needs of the population as a whole. Researchers should adopt methods that allow them to engage with, rather than exclude, these populations, but this requires a critical acknowledgement and evaluation of the potential limitations of the chosen strategies.

Conclusion Problems with sampling must be examined and discussed. Well-evaluated but limited research data are preferable to no information from groups that are hidden and hard to reach.

Implications for research or practice Engaging these populations in research can further professionals’ understanding of service provision.