Ketamine anesthesia was used in children to perform 200 outpatient procedures (mainly spinal taps, bone marrow aspirations and biopsies). Atropine was administered in advance and a ketamine dose of 1.8--2.0 mg/kg i.v. was sufficient in most instances. The general anesthesia allows calm and accurate performance of the necessary procedures. Ketamine can be used repeatedly and was preferred by the majority of children for subsequent procedures. The application of Diazepam (2 mg i.v. or 5 mg rectally) reduced unpleasant wake-up dreams in older children. The children were under close observation until consciousness was regained. They left the outpatient clinic attended by their parents approximately one hour after the procedure.