Two studies were conducted to investigate the use of cognitive/attentional distraction (via commercially available video games) to control conditioned nausea in pediatric cancer patients receiving chemotherapy. The first study compared the nausea severity in children who played video games during chemotherapy-related procedures with that of control-group children who did not play video games. The second study used a combined ABAB withdrawal and repeated measures analysis of variance design that incorporated baseline and intervention assessments within a single session. In both studies, video game-playing resulted in significantly less nausea. The introduction and withdrawal of the opportunity to play video games produced significant changes (reduction and exacerbation, respectively) in nausea. Although video games also reduced self-reported anxiety, the effects were weaker than those for nausea. Pulse rate and systolic/diastolic blood pressure were not consistently affected.