The psychoactive effects of using areca nut and its potential for dependence have been observed. However, the factors that create barriers to or promote chewing cessation are not well understood. This study aims to explore the behavioral changes of betel quid chewers who have been diagnosed with oral cancer within a transtheoretical model framework. Thirty oral cancer patients with betel quid chewing history were chosen for in-depth interviews. Qualitative content analysis was used to analyze the data and identify themes that described the behavioral changes of betel quid cessation. Our research showed that betel quid chewers with oral cancer typically experience four significant stages of behavior: pre-contemplation, contemplation, action, and maintenance. Each stage change was marked by specific characteristics. At first, chewers showed positive attitudes toward the psychoactive or social effects of betel quid. They then realized the negative effects of betel quid, such as dental or other physical problems. Some also realized that they were addicted to betel quid. When they decided to quit, most chewers reported going "cold turkey." Some chewers successfully quit betel quid and attributed it to willpower. Those quitting because of the loss of oral functions were unable to chew anymore, though some chewers had experienced a relapse. In the maintenance stage, ex-chewers reported overcoming their addiction; however, relapse was possible. In this study, those who quit betel quid because of oral cancer usually quit tobacco and alcohol as well, with a lesser chance of recurrence. As the maintenance of chewing betel quid is multifactorial, this study provides information for betel quid cessation and oral cancer prevention.