The article reviews research on a most promising contemporary concept of behavioral change - transtheoretical mode] of change. Multiple studies, primarily in the field of smoking cessation, provided strong empirical support for various model constructs. The key elements of the model, such as stages of change, processes of change, and outcome measures (decisional balance, self-efficacy and temptation) are reviewed. The comprehensive multi-dimensional nature of the model, and integration between its components is emphatized. The model's implications in terms of improving behavioral treatment and potential areas of implementation including addictive and nonaddictive problem behaviors are discussed.