This was a prospective multicenter observational study, aiming to explore the effects of acupuncture on smoking cessation in Hong Kong. From March of 2010 to August of 2015, a total of 5202 smokers were recruited based on inclusion criteria and treated with acupuncture for 8 weeks. As a result, 2940 subjects finished the study with a drop-out rate of 43.48%. The self-reported 7-day point abstinence rate was 34.00% in Week 8 and 18.40% in Week 52. The exhaled carbon monoxide level and the number of cigarettes smoked per day were reduced significantly after treatment. The time to relapse was calculated to be 38.71 days. In addition, "cigarettes smoked per day," "Fagerstrom Test for Nicotine Dependence," "total sessions of acupuncture," "whether finished 8 acupuncture treatments in the first month," and "total sessions of acupuncture" were believed to be essential factors for abstinence success. It was concluded that acupuncture was a safe method for smoking cessation and was effective in helping smokers to quit; therefore, acupuncture could be considered as one of the methods to help smokers quit. Further studies regarding the effect differences between acupuncture and medications were needed to clarify the overall benefits of acupuncture.