This study examined the behavioral variations of pediatric oncology patients, their parents, and the medical staff across phases of medical procedures. Child coping and distress behaviors, as well as the behaviors of the adults, were considered. Results indicated differences in both level and type of child distress, with distress peaking during the bone marrow aspiration. During the early phases, more anticipatory distress was observed, while later the distress was more demonstrative. The type, but not the level, of child coping varied by phase. During the early, nonpainful phases, more verbal coping (nonprocedural talk and humor by the child) was used, whereas during the later painful phases, there was more audible deep breathing. Certain adult behaviors were shown to be highly correlated with phase-specific coping by the child, whereas other adult behaviors were highly correlated with child distress throughout the procedure. © 1990 Association for Advancement of Behavior Therapy. All rights reserved.