Most research on cognitive processes in craving has been carried out in the laboratory and focuses on food craving. This study extends laboratory findings to real world settings and cravings for drugs or activities as well as food. Previous laboratory research has found that playing Tetris reduces craving strength. The present study used an ecological momentary assessment protocol in which 31 undergraduate participants carried iPods for a week and were prompted 7 times each day, by SMS message, to use their iPod to report craving. Participants reported craving target and strength (0–100), whether they indulged their previous craving (yes/no), and whether they were under the influence of alcohol (yes/no). Those randomly assigned to the intervention condition (n = 15) then played Tetris for 3 min and reported their craving again. Those in the monitoring-only control condition (n = 16) provided baseline craving data to test if Tetris reduced the incidence and strength of spontaneous cravings across the week. Playing Tetris decreased craving strength for drugs (alcohol, nicotine, caffeine), food and drink, and activities (sex, exercise, gaming), with a mean reduction of 13.9 percentage points, effect size f2 = 0.11. This effect was consistent across the week. This is the first demonstration that visual cognitive interference can be used in the field to reduce cravings for substances and activities other than eating.