Inflammatory conditions in selected organs increase the risk of cancer. An inflammatory component is present also in the microenvironment of tumours that are not epidemiologically related to inflammation. Compounds of the inflammatory tumor microenvironment include leukocytes, cytokines, complement components, and are orchestrated by transcription factors, such as NFkB and Stat3. Recent studies have begun to unravel molecular pathways linking inflammation and cancer. An intrinsic (driven by genetic events that cause neoplasia) and an extrinsic (driven by inflammatory conditions which predispose to cancer) pathway link inflammation and cancer. Smouldering inflammation in the tumour microenvironment promotes proliferation and survival of malignant cells, angiogenesis, metastasis, subversion of adaptive immunity, response to hormones and chemotherapeutic agents. Cancer-related inflammation represents a target for innovative diagnostic and therapeutic strategies.