Focus group interview is a method to probe an identified subject through a group's brain-storming discussion. Compared to individual interviews, collective inputs through a focus group interview not only enhance the interviewees' knowledge, but also create innovative ideas regarding the identified subject. It is more integrative than questionnaire-like. In this paper, the authors describe the framework of the focus group interview-group cohesion, discussion process, outcome, group composition, research setting, moderator, group process factors, and its application process in a cancer patient group. The purpose of this article is to share the author's experience in the application of a focus group interview and to motivate those who are interested in related studies considering the use of focus group interviews for data collection.