This TLFB scale is designed to assess recent cigarette, marijuana, and other drug use. The TLFB can be administered by an interviewer, self-administered, or administered by computer. It asks clients to retrospectively estimate their drug, marijuana or cigarette use 7 days to 2 years prior to the interview date. For cigarettes and marijuana, individuals are asked to estimate the number of cigarettes or joints smoked per day. For all other drug use, only frequency of use is captured (i.e., used or did not use). At this time, quantity estimates of other drug use are not meaningful. It is user friendly and flexible, with easy feedback and uncomplicated interpretation. The TLFB can be used as a clinical and research tool to obtain a variety of quantitative estimates of marijuana, cigarette, and other drug use. These quantitative estimates and drug use-consumption variables can be used to measure change in drug, marijuana, and cigarette use levels in outcome monitoring and evaluation studies. In several studies, data obtained with a method like the TLFB have been sensitive to changes in drug and marijuana use. The TLFB can also be used in clinical settings as a motivational advice feedback tool to analyze clients’ marijuana, cigarette, and other drug use and to increase their motivation to change (e.g., feedback at assessment, comparative feedback such as before and during treatment). It has been adapted for use with dual diagnosis patients, and is a good index of treatment-related change.