Chronic pelvic pain is discomfort or pain greater than 6 months in duration. It is, usually, of sufficient discomfort that it requires medical or surgical intervention. It represents a cost of over US$3 billion in the USA, and accounts for a large percentage of visits to the gynecologist and surgical procedures performed, such as laparoscopies and hysterectomies. The most common gynecological causes of this pain are endometriosis, adhesions, interstitial cystitis and vulvodynia; however, the pain can be caused by systems in the body other than urogenital including gastrointestinal, musculoskeletal, urinary tract and psychological problems. Diagnosis is sometimes difficult and treatment is often frustrating. This article describes efficient ways to diagnose chronic pelvic pain and possible treatments depending on the cause of the pain.Expert Rev. Obstet. Gynecol. 2(1), 37-50 (2007) Chronic pelvic pain (CPP) is pain of greater than 6 months duration of sufficient discomfort requiring medical or surgical intervention [1]. In women, it often occurs in the reproductive age group. The discomfort is usually localized in the pelvis, the abdominal wall below the level of the umbilicus, the lower part of the back and the inner aspects of the thighs. One of the difficulties with CPP is the lack of specific characteristics. Seeking medical assistance from a gynecologist for chronic pelvic pain is a very common practice. It has been estimated that one in three women have had pelvic pain during their lifetime [2][3][4] and over 9 million women (15% of the adult female population in the USA) have been treated for chronic pelvic pain [2]. In the USA, 10-15% of all gynecological referrals are for pelvic pain [5] and it is estimated that 40% of all laparoscopies [6] and over 10% of hysterectomies performed by gynecologists are for CPP [4,5]. The estimated amount of money spent yearly on treating this painful illness is over US$3 billion dollars [2]. Due to lack of specific symptoms, it can lead to unnecessary and additional work-ups (BOX 1).