The aim of this study was to examine the participation of adults in OECD countries in formal education and lifelong learning activities according to OECD Education at a Glance 2017 data. In the study, descriptive screening model was used as it was intended to enlighten and evaluate a situation. Document review was used to collect the data of the study. The data was obtained from C6 indicators of OECD Education at a Glace 2017 report. This indicator provided information on how many adults participated in educational activities in OECD countries and presented detailed analysis of the barriers to the participation of adults in these activities. These documents were primarily divided into two as "the participation levels of adults in formal education and lifelong learning activities" and "participation barriers". Then, the documents were examined and evaluated taking into account the research problems. According to the results of the research, the participation levels of the adults in the study in an educational activity to meet their educational needs varied. The barriers to participating in the educational activities of the adults in the survey were divided into four categories as; child care or family responsibilities, too busy at work, too expensive, and other. In the light of the findings obtained from the research, it is suggested that the causes and solution offers for low adult participation in lifelong learning activities in Turkey can be deeply analyzed with qualitative research and efforts can be made to encourage the adults to participate in these activities.