BackgroundThe purpose of this study is to assess attitudes toward premarital dating and sexual encounters in individuals aged 15–49 years in Tehran.MethodsUtilizing the attitudes section of an original cross-sectional study (n = 755) aimed at assessing sexual health needs of adults, this paper examined personal attitudes towards premarital dating, non-sexual relationships and sexual encounters in both male and female adults aged between 15–49 years. Multi-stage cluster random sampling and a validated/reliable questionnaire were used. Descriptive, bivariate and multivariate analyses were conducted using statistical software.ResultsThe results indicated that the majority of the participants were supportive of dating. Almost three-fourths of the males were more positively inclined towards non-sexual, yet tactile, affectionate interactions between unmarried males and females as opposed to only half of the females (70 % vs. 50.5 %). Also, males held significantly more liberal attitudes than females in their acceptance of premarital sex. On preserving virginity prior to marriage, 43 % of the males felt that it was important for a female to be a virgin, whereas only 26 % felt it was important for males to remain a virgin. Interestingly, more females (61 %) supported the importance of a female’s virginity compared with the importance of males’ virginity (48 %). This study showed that, being a male, of a younger age, single, and being less religious or being secular were important determinants of a liberal sexual attitude.ConclusionThese results might reflect a socio-cultural transition in the sexual attitudes of different age groups of participants - a phenomenon that will need empirical studies to unpack in the Iranian socio-cultural context.