ObjectivesWe compared the smoking prevalence, smoking knowledge, attitudes and practices (S-KAP) between smoke-free campuses (SFCs) and non-SFCs (NSFCs) and determined the associated factors of smoking status and S-KAP.DesignCross-sectional study.SettingsThe research was conducted in four public universities in Malaysia; two SFCs and two NSFCs.ParticipantsStudents and staff from SFCs (n=1063) and NSFCs (n=1040).Main outcome measuresCompared the smoking prevalence, S-KAP between SFCs and NSFCs and determined the associated factors.ResultsThe prevalence of smokers among the SFC and NSFC respondents was 5.2% and 6.7%, respectively. University type and smoking attitude were significantly related (p=0.02). At the SFCs, the factors associated with becoming a smoker were male gender (p<0.001), monthly income ≥RM3000 (p=0.02), positive smoking attitude (p=0.003) and positive smoking practice (p<0.001); at NSFCs, the associated factors were male gender (p<0.001), low smoking knowledge (p=0.004), positive smoking attitude (p=0.001) and practice (p<0.001). The factors associated with good smoking knowledge were female gender (SFCs: p=0.001; NSFCs: p=0.004), and monthly income ≥RM3000 (NSFCs: p=0.02). Male respondents were likely to have positive smoking attitudes (SFCs: p<0.001; NSFCs: p<0.001) and negative smoking practices (SFCs: p<0.001; NSFCs: p<0.001).ConclusionOverall, smoking prevalence, knowledge and practice were not much different between SFCs and NSFCs. However, there was a significant relationship between university type and smoking attitude due to the existence of the SFC policy likely rendering smoking a less acceptable social norm. Continual education programmes on smoking harms and smoking cessation strategies are highly recommended to aid the SFC policy in preventing secondhand smoke in universities.