Electronic nicotine delivery systems (ENDS), often called e-cigarettes, have become ubiquitous in the United States and globally, and their use has led to considerable research, discussion and debate.  Some argue they are a public health threat that might cause smokers to not quit or might cause children who use them to eventually switch to combustible cigarettes.  Others have argued that they have great potential to reduce combustible tobacco use, and might even be an effective smoking cessation treatment.   This talk will provide an overview of ENDS, their use, and risks, but will focus on their potential for tobacco treatment.