Approximately 50 years of research on rapid toilet training (RTT) first used by Azrin and Foxx (1971) indicates RTT is effective for teaching individuals with intellectual and developmental disabilities (IDD) independent toileting routines. Professionals focused on toilet training may be familiar with RTT procedures but be less informed about the frequency and duration of RTT application. We systematically reviewed the intervention research focused on rapid toileting training to better understand the intensity of RTT in the intervention research literature. Results indicated intensity varied considerably by study but suggest RTT will require approximately 30-min inter-sit intervals for six days per week, for a total of 373 hours to produce the effect. Implications for research and practice are discussed.