Objectives. The present study aimed to examine the influence of psychosocial factors on smoking behaviour in young adults. Design. The study used a cross-sectional exploratory design. Methods. The participants were 204 young adults who were students at the University of Edinburgh. A questionnaire was administered which included questions to gain social and demographic information including age, social class, income, smoking history and other health behaviours. Additional measures were included to assess personality (IPIP; Goldberg, 2002), emotional intelligence (Schutte et al, 1998) and perceived stress (Cohen et al, 1983). Results. Perceived health (r=-0.17, p<0.05), age, social class, income (p<0.01), alcohol units (p<0.05) and exercise (r=-0.15, p<0.05) were associated with smoking consumption. Extraversion (r=-0.29, p<0.05), perceived stress (r=-0.41, p<0.05), age (r=0.41, p<0.01) and social class (p<0.05) were correlated with age at starting smoking. Multivariate analysis revealed age, income and social class were independent predictors of smoking consumption accounting for 30% of the variance. For age at which people start smoking, extraversion and perceived stress accounted for 11% of the variance. However after adjustment for covariates (age, sex, social class, income, alcohol and exercise), Extraversion alone remained an independent predictor, accounting for 8% of the variance in the age at which people start smoking. Conclusions. Older age, lower social class and higher income were associated with smoking consumption in university students. Higher extraversion was a direct predictor of the age at which people started smoking. The findings show that social and psychological variables are important predictors of smoking behaviour. The results are discussed in terms of implications for health promotion and intervention programs.