A group of professionals knowledgeable in the field of STDs met in Atlanta, GA, on September 26-28, 2000, and consulted with the CDC to produce these guidelines. This information updates the 1998 Guidelines for Treatment of Sexually Transmitted Diseases (MMWR 1998; 47(No. RR-1)). There are new alternative regimens for scabies, bacterial vaginosis, early syphilis, and granuloma inguinale. An expanded section is provided on the diagnosis of genital herpes (including type-specific serologic tests). There are new recommendations for treatment of recurrent genital herpes among persons infected with human immunodeficiency virus (HIV). A revised approach to the management of victims of sexual assault is described. There are expanded regimens for the treatment of urethral meatal warts. Hepatitis C is included as a sexually transmitted infection. Education and counseling are emphasized for persons infected with human papillomavirus. The diagnostic evaluation of congenital syphilis is clarified. Information is presented regarding the emergence of quinolone-resistant “Neisseria gonorrhoeae” along with the implications for treatment. Recommendations are provided for vaccine-preventable STDs, including hepatitis A and hepatitis B. 5 tables, 114 references