Cancer is the greatest disease burden in Korea. Cancer screening can reduce the burden of cancer but cancer screening rates among Koreans remain low. The purposes of this study were to a) understand Koreans' beliefs and knowledge about cancer screening, and b) explore preferred strategies for increasing cancer screening utilization.We conducted a descriptive, qualitative study using eight face-to-face focus groups with a total of 64 Koreans aged 40 and over. Participants answered semi-structured, open-ended questions assessing their experiences with, and beliefs, knowledge, and opinions about, cancer screening. All interview data were recorded and analyzed in the context of the health belief model (HBM).The most important themes that emerged from the focus group data were (a) perceived susceptibility (most of the participants believed they were not susceptible to cancer; those who perceived themselves susceptible to cancer were reluctant to express it); (b) perceived benefits (early detection and feelings of relief after cancer screening were benefits; participants had screening because they wanted to take advantage of the Korean government's Medical Payment Support program for cancer patients who have participated in the National Cancer Screening program); (c) perceived barriers (no symptoms; self-care when having symptoms; widespread distrust of tests, doctors, and hospitals; unkind health care providers; the financial burdens of advanced cancer screening tests; and the discomfort during cancer screening); and (d) knowledge of the causes of cancer (incorrect knowledge including beliefs that stress, personality, and body overuse cause cancer). Almost all of the participants were very knowledgeable about the seriousness of cancer and were confident that they were able to have cancer screening. Participants preferred strategies of cancer screening using group interventions with family or friends; various information delivery methods; information emphasizing the importance of cancer prevention; convenient, free, or inexpensive services; and kind health care providers.This HBM-based research suggests that beliefs in low susceptibility to cancer, many barriers to cancer screening, and incorrect knowledge should be the foci for increasing cancer screening rates in Koreans. Interventions could change individual cultural beliefs and increase knowledge as well as the quality of health care for Koreans.