Background: The extent of the differential spread of HIV around the world remains incompletely explained. This paper examines the extent to which five explanatory variables (circumcision prevalence, condom usage, STI treatment coverage, number of sex partners, partner concurrency) are correlated with peak HIV prevalence rates at a country level. Methods: We performed linear regression analysis to measure the association between each of the independent variables and the national peak HIV prevalence rates for 15 - 49 years old. Results: Our analysis shows a strong positive association between peak HIV prevalence and the prevalence of partner concurrency (rho = 0.853; P = 0.001). There was no association between peak HIV prevalence and circumcision prevalence (rho = 0.118; P = 0.161), condom usage (rho = 0.048; P = 0.794), STI treatment coverage (rho = 0.143; P = 0.136) and number of sex partners (rho = 0.134; P = 0.298) at a global level. There was however a strong negative association between peak HIV prevalence and circumcision prevalence when the analysis was limited to countries within sub Saharan Africa (rho = -0.659; P = 0.000). Sub Saharan Africa had the second and third highest circumcision rates in the world when the circumcision prevalence thresholds were set at 80% and 20% respectively. Conclusions: Differences in the prevalence of circumcision likely influence differential peak HIV prevalence within sub Saharan Africa but are implausible causes for the higher HIV prevalence in this region. The close association found between concurrency and HIV prevalence requires replication in further studies.