C-reactive protein (CRP) is a widely used systemic biomarker for diagnosing acute and chronic inflammation. During the past decade, serum CRP has been re-emphasized by extending its clinical use to the prediction or diagnosis of cardiovascular diseases and other conditions, particularly malignancies. Serum CRP has also been found to be elevated in patients with many malignancies, implying a close linkage between inflammation and malignancy. Prospective studies have shown a higher risk of developing cancer in those with elevated serum CRP. CRP is produced by hepatocytes in response to inflammatory cytokines, particularly, interleukin-6 from the tumor microenvironment. Preoperative CRP levels are parallel to the progression or pathological stages of malignancies, including gastric cancer in patients in our series. Elevated CRP is a determinant predictor of lower survival rates in patients with several cancers, including esophageal, colorectal, hepatocellular, pancreatic, urinary bladder, renal,ovarian and cervical cancer, after surgical resection. The measurement of serum CRP is simple, cheap, and available in daily practice. It can serve as an additional prognostic predictor for survival and post-treatment monitoring in cancer patients. In the future, CRP-lowering agents might offer a promising benefit in the prevention and therapy of many different types of cancer.