BACKGROUND Despite restrictive social norms, there is increasing evidence that youth in India engage in premarital romantic and sexual partnerships. However, information on how they initiate and build these relationships is scarce, even though it is vital for addressing the needs of young people. METHODS Attitudes toward and behavior within romantic partnerships were examined using data collected in 2004 from unmarried youth (583 males and 475 females, aged 15-19) living in economically disadvantaged neighborhoods in Delhi, India. Associations between specific attitudes or behaviors and age, gender and sexual experience were determined using Fisher's exact tests. RESULTS Sixty-two percent of males and 53% of females reported that someone of the opposite sex had expressed an interest in them; 86% of males and 63% of females reported feeling good about it. In addition, 67% of males and 47% of females reported that they liked someone from the opposite sex. Compared with females, males were more likely to seek information about the person they were interested in (76% vs. 61%), and to engage in heterosexual premarital sex (32% vs. 6%). Females were less likely than males to report that it is okay to engage in premarital sex if the male and female love one another (14% vs. 33%). For both males and females, television and films were the most popular source of information on issues related to sexual health. CONCLUSIONS Gender disparities in premarital romantic partnership formation and the experience of sexual relations make a strong case for sexuality education programs tailored to the different experiences and circumstances of young men and women.