A treatment outcome study was conducted to compare the efficacy of cognitive behavior therapy (CBT) versus general anesthesia in alleviating the distress of 18 pediatric cancer patients (ages: 3-12 years) undergoing bone marrow aspirations (BMAs). CBT and short-acting mask anesthesia were delivered within a repeated-measures counterbalance design. Results indicated that children exhibited more behavioral distress in the CBT condition for the 1st minute lying down on the treatment table. However, parents rated significantly more behavioral adjustment symptoms 24 h following the BMA when their children had received anesthesia. No differences were found in childrens' and parents' preference for CBT versus anesthesia.