Chronic, heavy marijuana smokers and non-smoking controls completed a novel marijuana-specific Go/No Go task to measure inhibitory control. The task included marijuana-related and neutral images. Marijuana smokers had significantly slower reaction times overall and specifically for marijuana stimuli compared to controls. Within the marijuana smoker group only, accuracy was higher for marijuana versus neutral stimuli, highlighting an attentional bias for drug cues. The results suggest the task successfully detected inhibitory control impairments and drug cue reactivity in marijuana smokers relative to controls.