This study aimed to examine the use of a predictive stimulus (Time Timer) and delayed reinforcement to increase appropriate waiting behavior in a child with developmental disabilities and problem behavior maintained by access to tangible items and activities. The study employed a changing criterion design across settings to gradually increase reinforcement delay from 1s to 10 min. Firstly a baseline phase was conducted to measure the duration of appropriate waiting behavior to access tangible reinforcers/activities. Phase 2 involved the use of a red cue card and the verbal instruction "wait". Phase 3 involved the introduction of the Time Timer with the cue card attached, and the verbal instruction "wait". Finally, Phase 4 utilised the Time Timer without the cue card. This method was an effective strategy for increasing appropriate waiting behavior with this participant in a school setting. The role of adding a concurrent activity during the reinforcement delay, using cues to predict reinforcement, future generalization, maintenance and the teaching of functionally equivalent skills are discussed.