The responses of 387 smokers and 988 nonsmokers obtained in a populati
on-based survey in Ontario, Canada, were compared with regard to knowl
edge, attitudes, and predicted behavior concerning restrictions on smo
king. Responses were tabulated as percentages and weighted according t
o the sample design. Nonoverlapping 95% confidence intervals provided
evidence to reject the null hypothesis. Although smokers were found to
be less knowledgable about the health effects of smoking and environm
ental tobacco smoke, more than 90% of both smokers and nonsmokers agre
ed with restrictions on smoking in 14 specific settings; for some sett
ings, they disagreed on the extent of restrictions. The groups differe
d concerning specific bans on cigarette sales, but support was uniform
ly strong for bans in hospitals, controls on vending machines, and enf
orcement of the law prohibiting sales to miners. Clear majorities of b
oth groups agreed that local government should enact and enforce restr
ictions. Smokers were more likely than nonsmokers to predict that smok
ers would comply with more restrictions, and most smokers indicated th
at they, themselves, would comply. We conclude that general health edu
cation should be bolstered by strategies specifically targeted at smok
ers. There is a strong basis across the population for restrictions to
reduce exposure to environmental tobacco smoke; support for the role
of local government in this regard is clear. Noncompliance with more r
estrictions is unlikely to present enforcement problems. Measures limi
ting the physical access of youths to tobacco will be widely supported
, but strategies to increase support for tax measures are needed.