Health care planning for chronic pelvic pain (CPP), a crucial explanation for morbidity amongst women is hampered thanks to lack of clear collated summaries of its basic epidemiological data. We systematically reviewed worldwide literature on the prevalence of various sorts of CPP to assess the geographical distribution of knowledge , and to explore sources of variation in its estimates. We identified data available from Medline (1966 to 2004), Embase (1980 to 2004), PsycINFO (1887 to 2003), LILACS (1982 to 2004), Science Citation index, CINAHL (January 1980 to 2004) and hand searching of reference lists. Two reviewers extracted data independently, employing a piloted form, on participants' characteristics, study quality and rates of CPP. We considered a study to be of top quality (valid) if had a minimum of three of the subsequent features: prospective design, validated measurement tool, adequate sampling method, sample size estimation and response rate >80%. We performed both univariate and multivariate meta-regression analysis to explore heterogeneity of results across studies.