Purpose: The aim of this qualitative study was to identify the experiences of smoking and smoking cessation in out-of-school youth. Methods: The participants were 12 out-of-school youths belonging the Youth support Center located in A and B area. The data were collected from January 8 to 15, 2018, using a FGI(Focus Group Interview). The main sub-domains of the experiences of smoking and smoking cessation in out-of-school youth by 7 questions were categorized from the intrapersonal, interpersonal, organizational, and community factors in ecological model. Results: The motivation, continuity, disadvantage of smoking experiences of out-of-school youth were analyzed in 10 sub-domains (curiosity, friend's invitation, mood of adapted group, habit, relieving stress, providing breaks, friendship, physical damage, loss of money, a bad sight of smoker). The reason, difficulty, advantage, reason for restarting smoking cessation experiences of out-of-school youth were analyzed in 15 sub-domains (physical damage, for future hope, invitation of others, influence of family, weight gain, emotional stress, worsening friendship, improvement physical condition, saving money, better relationships, not with bad friends, withdrawal, smoking of friends, drinking, separated a lover). Conclusion: Based on the results, it is expected that a Specialized Smoking Cessation Education Program will be developed for out-of-school youth's health activities in ecological factors.