Background: Hypoalbuminemia often reflects malnourishment. Malnourished patients have a higher risk of mortality; complications and prolonged hospital stay. Objectives: The effects of hypoalbuminemia in early postoperative complications, organ failure and immune function in patients undergoing major cancer surgery. Study design: A randomized double- blind trial. Setting: Academic medical center. Methods: Forty patients underwent elective major oncological surgery were divided into two groups. Group I: serum albumin >35 g/L and Group II: serum albumin ≤ 35 g/L. Preoperative level of IL1, total lymphocytic count and neutrophilic count were determined. patients were monitored daily for major postoperative complications, including, Acute Respiratory Distress Syndrome (ARDS), sepsis, multi-organ dysfunction syndrome (MODS), renal failure, heart failure, respiratory failure, pneumonia/respiratory tract infection, major thromboembolic event, wound infection / dehiscence, anastamotic leak and fistula formation. SOFA score recorded on the day of admission to the ICU and every 48 hours until discharge. The length of stay in the ICU was measured from admission to the ICU until discharge. Complete blood picture, arterial blood gas, liver function, interleukin IL1 and kidney function were done on first, third, fifth and seventh postoperative day. Results: Postoperative complications were higher in group II compared to group I. Also, the length of stay was proved to be statistically significant in group II (9.60 ± 3.59 days) compared to group I (6.95 ± 0.69 days) (P = 0.002). Serum level of IL1, were statistically significant increased in group II compared to group I on first, third and seventh postoperative days. There was no statistically significant difference between two groups in Total lymphocytic count in all follow up days and statistically significant increase in neutrophilic count on group II compared to group I on first, third and seventh postoperative days. Finally there was a statistically significant increase in SOFA score in group II compared to group I in all follow up days. Limitations: This study is limited by its small sample size. Conclusion: preoperative hypoalbuminemia increases the risk of postoperative complications and length of stay in ICU after major cancer surgery.