Background Ensuring individual free and informed decision‐making for research participation is challenging. It is thought that preliminarily informing communities through ‘community sensitization’ procedures may improve individual decision‐making. This study set out to assess the relevance of community sensitization for individual decision‐making in research participation in rural Gambia. Methods This anthropological mixed‐methods study triangulated qualitative methods and quantitative survey methods in the context of an observational study and a clinical trial on malaria carried out by the Medical Research Council Unit Gambia. Results/discussion Although 38.7% of the respondents were present during sensitization sessions, 91.1% of the respondents were inclined to participate in the trial when surveyed after the sensitization and prior to the informed consent process. This difference can be explained by the informal transmission of information within the community after the community sensitization, expectations such as the benefits of participation based on previous research experiences, and the positive reputation of the research institute. Commonly mentioned barriers to participation were blood sampling and the potential disapproval of the household head. Conclusion Community sensitization is effective in providing first‐hand, reliable information to communities as the information is cascaded to those who could not attend the sessions. However, further research is needed to assess how the informal spread of information further shapes people's expectations, how the process engages with existing social relations and hierarchies (e.g. local political power structures; permissions of heads of households) and how this influences or changes individual consent.