Women having sex with women are at risk for a full range of viral and bacterial sexually transmitted infections (STI) and associated conditions, with the available evidence strongly supporting the need for attention to studies of transmission of C. trachomatis, HSV, HPV and BV. While there is a paucity of data on most STI in WSW, relatively solid data do speak to the need for adherence to standard screening guidelines for cervical cancer and C. trachomatis. Health care providers should apply their skills in sexual risk assessment to all women, including WSW, with particular effort towards inquiring about potential higher risk male partnerships and illicit drug use. Evidence also supports that while WSW may be knowledgeable about safer sex measures, relatively few practice them. Further research on behaviors and mechanisms of disease acquisition and transmission among WSW, including exploration of higher risk partnerships and behaviors, is needed.