Li WHC, Ho KY, Wang MP, et al. - A Randomized Clinical Trial was designed to analyze the effectiveness of a brief intervention based on self-determination theory for smoking cessation (immediate or progressive) among Chinese smokers presenting at emergency departments (EDs) in Hong Kong. This trial performed at the EDs of 4 major acute care hospitals in different districts of Hong Kong. Researchers recruited a total of 1,571 smokers 18 years or older who presented at 4 major EDs between July 4, 2015, and March 17, 2017, were randomized into an intervention group (n = 787) and a control group. For smokers, this brief, low-cost self-determination theory-based intervention showing at EDs effectively increased the biochemically validated quit rate at 6 months. Whether given routinely, such a simple intervention may propose a cost-effective and sustainable method to enhance many smokers quit smoking.