This document reviews research on the foot-in-the-door (FITD) social compliance technique. It identifies several psychological processes that may influence compliance in a FITD situation, such as self-perception, reactance, conformity, consistency, attributions, and commitment. Some processes increase compliance while others decrease it. The effectiveness of FITD depends on the relative strength of these different processes. The review examines studies that meet criteria for a clear FITD manipulation and finds the technique reliably but modestly increases compliance. However, explanations beyond self-perception may be needed to understand all FITD results.