Inferior mesenteric plexus block(IMPB) is a nerve block for lower abdominal pain originating from GI tract of distal transverse colon to sigmoid colon and other polvic organ where the inferior mesenteric plexus contains visceral afferent fibers of that organ. We performed IMPB on two patients with lower abdominal pain. Case I: 61 year old female diagnosed with cancer of stomach and uterine cervix and carcinomatosis, experienced complete relief from pain for a period of 7 months after IMPB. Case II: male, 28 years old, who had contracted cancer of the descending colon with obstructive jaundice and pancreatitis had complained of pain in the whole of the abdominal area. IMPB was performed for lower abdominal pain. Seven days after, a celiac plexus block was also performed for upper abdominal pain. The patient complained of recurring pain in the left & upper lower abdomen 30 days after the IMPB. The intensity of the pain was visual analogue scale 4 and it was managed by continuous epidural block. Conclusion: It is our recommendation that IMPB is a reliable method for treatment of lower abdominal pain originating from malignant condition of GI tract from distal transverse colon to sigmoid colon and urinary bladder.