Objectives: To evaluate the current knowledge about interstitial cystitis pathophysiology and its relationship with rheumatic, autoimmune and chronic inflammatory diseases., Methods: Literature search under "interstitial cystitis pathophysiology" either clinical or experimental trials and reports, in Medline, PubMed, Digital Urology Journal and Doctor's Guide, in addition to our own clinical research experience results., Results: Both human and experimental trials show resemblances between interstitial cystitis and rheumatic, autoimmune, and chronic inflammatory diseases on clinical presentations, pathophysiology. Some interstitial cystitis patients show the bladder infiltrated with specific mononuclear cells, high incidence of circulating antinuclear antibodies, good response to anti-inflammatory and/or immunosuppressive therapies. Interstitial cystitis in association with rheumatic, autoimmune and chronic inflammatory diseases is very common. Many patients with systemic lupus erythematosus, Sjögren syndrome and fibromyalgia syndrome show antibodies against urothelium and/or muscle cells and/or other connective tissue components of urinary bladder. Systemic lupus erythematosus and Sjögren syndrome are the autoimmune diseases which bear strongest similarity with interstitial cystitis. Moreover, rheumatoid arthritis, chronic pelvic pain syndrome, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, Evan's syndrome and atopic dermatitis share some pathogenic characteristics., Conclusions: Nowadays, interstitial cystitis pathophysiology is unknown. Based on clinical presentations, epidemiology, pathology and laboratory findings and treatment response, there is an important correlation among interstitial cystitis and rheumatic, autoimmune and chronic inflammatory diseases. These disorders may share some pathophysiologic mechanisms. Rigorous studies of pathophysiology of these group of diseases are needed to confirm consistently this approach for such conditions.