Pain management is an important component in cancer management. The administration of painful injections to children in an oncology clinic can create difficulties. This study was undertaken to determine the role of oral ketamine to modify the response to pain. Between 1996 and 1999,6324 patients attended a tumour clinic in a developing country teaching hospital. Forty eight children required cytotoxic injections on 103 occasions. These children were subdivided into 3 groups according to the year of attendance: 1996,1997 and 1998/8. each group was premeded differently. The first group received ketamine 4.5mg/Kg; the second received ketamine Gmg/Kg and the third had ketamine 6mg/Kg with diazepam O.lmg/Kg. The esponse to pain in each group was evaluated by using an observer based scoring system. The visual analogue scale was not used. The study showed that oral ketamine is an effective and safe drug for use in a clinic setting. However, its action was not always predictable due to a number of confounding factors. A phenothiazine should be routinely used in these children to enhance the effectiveness of ketamine and to diminish the likelihood of its well-known side effects. Further studies using less costly lower doses of ketamine is recommended. Key words: Oral Ketamine, Premedication and Oncology