Abstract Purpose: The United States has the highest rate of teen pregnancy of any industrialized nation. Adolescents who have their first sexual intercourse at a young age are at increased risk for teen pregnancies and acquiring a sexually transmitted disease. This study examines predictors of early onset sexual intercourse in male and female residents of the United States. Methods: A nationally representative sample of N=7,643 females and N=4.928 males ages 15-44 was procured from the 2002 National Survey of Family Growth (NSFG), Cycle 6. Age at first sexual intercourse was used to define early onset of sexual debut(<18 years). Socio-demographic and behavioral characteristics of the respondents, demographic and selected reproductive characteristics of the respondent's parents were examined using multiple logistic regression modeling. Results: Non-fispanic black, being raised without both parents, having a mother less than 18 years old at the age of first birth and age difference between partners were significant predictors of early onset of sexual intercourse for both males and females. Maternal education less than high school was a significant protective factor for female respondents [OR=0.72 (95%CI=0.58- 0.90)] and paternal education completed high school only [OR=1.4 (95% CI=l. 1-1.7)] was a significant risk factor for male respondents. Conclusions: Racelethnicity, age difference between partners, not being raised by both parents, having a mother who had her first birth before the age of 18 and parental education are important predictor variables. Further study should be conducted to investigate the protective effect of lack of maternal education for female respondents. Intervention programs for teen pregnancy and sexually transmitted infection prevention should target these at risk groups.