The age at which American adolescents first experience sexual intercourse continues to decline. Approximately half of all American females and two-thirds of all males have experienced coitus by 17 years of age.1,2 For those who begin having intercourse before age 18, 45% of females report having had four or more partners,3 and males report having had an average of five partners.2 Most adolescent females report that their first experience was unplanned.4 More than 85% have first coitus before seeking professional advice about preventing pregnancy or sexually transmitted diseases (STDs). The earlier the first coitus, the longer the interval until such advice is sought. There are a number of consequences of unprotected coitus including pregnancy, often unwanted, and exposure to STDs that may adversely affect pregnancy outcome, damage the reproductive system, or even threaten life.5,6 An estimated 4% of students in grades nine through 12 have a history of a STD.3 The number of adolescents with acquired immunodeficiency syndrome (AIDS) has increased 77% since 1989.7 The 10-year latency period between infection with the human immunodeficiency virus (HIV) and development of symptoms suggests that many AIDS patients were probably infected as teenagers.5 For females, early intercourse, repeated infections, and multiple partners greatly increase the risk of cervical cancer and infertility.5 Although the use of contraception, especially condoms, can prevent many of these conditions, teenagers do not use contraceptives effectively.3 The 1985 Guttmacher Report found that despite levels of sexual activity comparable to their European counterparts, the teenage pregnancy rate in the United States was two to five times higher than in other developed countries.8