Pre-anesthetic assessment of laboratory findings in proposed operative patients is one of the most important procedures in evaluating the patients condition. The more diffuse and minutely the findings are carried out, the better the results are in controlling the patients during and after anesthesia. The serum electrolytes are the most essential laboratory findings in ascertaining whether or not the body components deviate beyond the norm. If there should be a severe deterioration of the major electrolytes for any cause, the physiological response of the various mechanisms of the body tissue will attempt to restore the normal status. At times, it is impossible to obtain normal conditions because of too serious impairment of the cellular functions due to severe electrolyte imbalance. The authors studied the pre-anesthetic major serum electrolytes in elective operative cases retrospectively and the results were classified into two groups of GI diseases and others. These results were compared with the normal values and ranges. Although most of the mean values of our data shifted to the lower level of the normal, the deviations were still within the normal range. Even though the lower levels were observed in a few more incidents in the GI diseases than in the other disease group, still these were of no great significance.