Few studies have examined reasons why those with low socioeconomic status do not adequately receive cancerscreening. We therefore conducted a qualitative study to assess the barriers to cancer screening in people with lowsocioeconomic status, and to examine the reasons why Medical Aid Program (MAP) recipients do not participatein the National Cancer Screening Program (NCSP). A focus group methodology was used. Participants includedMAP recipients (men aged 45-79 years, women aged 35-79 years) who had been invited to cancer screening atleast twice based on the NCSP protocol, but had not been screened for any cancer from 2009-2012. We recruitedparticipants living in the cities of Goyang and Paju. A total of 23 MAP recipients participated in four focus groupdiscussions, including 12 men and 11 women. In this qualitative study, we identified six barriers to screening:lack of trust in the NCSP and cancer screening units; fear of being diagnosed with cancer; discomfort or painfrom the screening procedure; lack of time, lack of knowledge about cancer screening or lack of awareness ofthe existence of the NCSP; physical disability or underlying disease; and logistic barriers. Interventions such asindividualized counseling, letters and reminders, or other individually-targeted strategies, especially for thosewith lower socioeconomic status are required to increase participation and reduce disparities in cancer screening.