OBJECTIVE To determine the value of routine pre-operative investigations in children scheduled to undergo routine minor elective surgical procedures under general anesthesia. METHODS We conducted a retrospective chart review of 342 children who presented for elective minor surgical procedures in the Division of Pediatric Surgery, King Khalid University Hospital, Riyadh, Saudi Arabia from January 2004 to December 2004. Pre-operative investigations (full blood count, urea and electrolytes) were analyzed in terms of frequency of abnormalities and whether or not the preoperative management was changed when the results were abnormal. We also examined the relationship between abnormal results and complications and the costing of the tests. RESULTS During a one year period, 342 children were admitted to the pediatric surgical unit for routine minor elective surgery. A total of 684 tests were performed, of which 63 (9.2%) were abnormal. Nine children had abnormal hemoglobin results (the lowest was 8.5 g/dL). Thirty-two children had clinically insignificant platelets or white blood cell counts. There were 22 abnormal electrolyte results. These abnormalities were very insignificant. No case was postponed because of these investigations. Three complications arose, none of which could have been predicted by the pre-operative screening tests. CONCLUSIONS This results indicate that pre-operative blood testing in children undergoing minor surgical procedures has very limited value in patient management. It may be unpleasant for the patient and parents. A careful history and physical examination are of greater importance than routine laboratory test in determining a child's fitness for surgery.