Peer pressure becomes a perturbing and problematic phenomenon as children grow seeing their peers as role models. Peer pressure is a social institution that modifies adolescents' behaviours by making them indulge in risky behaviour such as smoking at early age. This phenomenon has indeed found its way into our tertiary institutions and among our youths who are leaders of tomorrow. This study examined peer pressure and tobacco smoking among undergraduate students of the University of Calabar, Nigeria. Data were obtained through the administration of a structured questionnaire to one hundred and twenty respondents in two well known and patronized restaurants and bars directly opposite the University of Calabar's small gate. Results indicated that 46 per cent of tobacco use among undergraduate students were accounted for by peer pressure, while the ANOVA result indicated that peer pressure had significant influence on undergraduate students' tobacco use (F = 4.069, p<0.05); the model further revealed that a unit increase in peer influence factor would result in 62% unit rise in the percentage of undergraduates that make use of tobacco substance. Result of independent samples test showed that the frequency of tobacco use differs between sexes (t = 3.100, p<0.05). This study therefore revealed that the frequency of tobacco use among undergraduate student in Nigeria's university environment was on the increase. In order to reduce this phenomenon which indeed has found its way into our campuses, the study suggested among other measures the implementation of programmes that will integrate concerned authorities in order to reduce the number of adolescent smokers and realize the vision of better health for Nigerian youths who are leaders of tomorrow by the year 2020.