Observed 51 children with cancer, their parents, and their physicians during routine bone marrow aspirations and lumbar punctures. Child distress was measured via the Observational Scale of Behavioral Distress (OSBD); adult behaviors were coded via the Child Adult Medical Procedure Interaction Scale (CAMPIS). In general, physicians were less verbally interactive than parents both before and during the procedure. As expected, several parent behaviors were positively related to child distress. However, physician behaviors were uniformly negatively related to child distress. Findings are discussed in terms of the physician-patient relationship and the possible role of physicians as change agents in reducing child distress during invasive procedures.