Bone marrow aspirations (BMA's) are a highly stressful event for pediatric cancer patients, as well as their parents. The primary aims of this study are: a) to evaluate the efficacy of a stress-reduction program for parents, and b) to determine if the efficacy of Valium in reducing children's distress associated with BMA's can be significantly improved upon by the addition of a cognitive-behavioral intervention package. Subjects will be 75 English- and Spanish-speaking leukemia patients, ages 4-12, and their parent(s). The design of the study is a 2 (Child Intervention Conditions) x 2 (Parent Intervention Conditions) x 2 (Trials) mixed factorial design. The intervention conditions for the child include a Valium only condition and Valium plus a Cognitive Behavior Therapy Package (modeling, breathing exercises, positive reinforcement, imagery-distraction, and behavioral rehearsal) condition. The intervention conditions for the parent(s) include a no intervention condition and a "Stress Inoculation" intervention condition, the components of which include cognitive restructuring, relaxation, and attention distraction. Subjects will be in the study for 2 consecutive BMA's: a pre-intervention baseline procedure and a post-intervention BMA. Dependent measures of children's distress include behavioral observations, self-reports of fear and pain, and physiological measures (pulse and blood pressure). Parental distress will be measured through self-report measures of anxiety, coping difficulty, and muscle tension, physiological measures of distress (pulse and heart rate), and a Cognitive Distortions Scale. Data analysis will be conducted using 2x2x2 analyses of variance. The study should be a significant contribution to the literature in that the issue of reducing parents' stress associated with their children's BMA's has never before been addressed empirically. Furthermore, this study may lead to the discovery of ways to reduce children's distress to the lowest levels that would be realistically obtainable.