Objectives Examine the patterns of cigarette smoking and e-cigarette use (vaping), the perceived harm of e-cigarettes compared with tobacco cigarettes, and associations between smoking and vaping with student characteristics. Design Cross-sectional studies. Setting The University of Queensland (UQ), Australia and eight New Zealand (NZ) universities. Participants Students at UQ: 4957 (70.8% aged <25 years, 63.0% women) and NZ: 1854 (82.5% aged <25 years, 60.1% women). Methods Χ2 tests compared smoking by age and gender, and vaping by age, gender and smoking status. Two-sided p<0.05 was considered significant and 95% CIs reported where appropriate. Multinomial logistic regression examined associations between smoking and vaping (exclusive smoking, exclusive vaping, dual use and non-use) with age, gender and student type (domestic vs international). Results Smoking (UQ vs NZ, 95%CI): ever 45.2% (43.8% to 46.6%) vs 50.0% (47.7% to 52.3%), current 8.9% (8.1% to 9.7%) vs 10.4% (9.1% to 11.9%) and daily 5.2% (4.6% to 5.8%) vs 5.6% (4.6% to 6.7%), and not smoking in indoor 98.3% vs 87.7% or outdoor smoke-free spaces 83.8% vs 65.3%. Vaping (UQ vs NZ, 95%CI): ever 20.9% (19.8% to 22.1%) vs 37.6% (35.4% to 39.9%), current 1.8% (1.5% to 2.2%) vs 6.5% (5.4% to 7.7%) and daily 0.7% (0.5% to 1.0%) vs 2.5% (1.9% to 3.4%), and not vaping in indoor 91.4% vs 79.6% or outdoor smoke-free spaces 84.4% vs 71.3%. Of respondents, 71.7% (70.3% to 73.2%) vs 75.3% (72.9% to 77.6%) perceived e-cigarettes as less harmful than tobacco cigarettes. Men were more likely than women to smoke and vape, and to believe that e-cigarettes are less harmful. Regression models containing all predictors for smoking and vaping were significant and the effect of gender was significant for dual use, exclusive smoking and exclusive vaping (all p<0.01). Men had higher odds for smoking, vaping or dual use. Conclusions Results suggest significant differences in patterns of smoking and vaping of university students in Australia and NZ, and a strong influence of gender on smoking and vaping.