Childhood obesity is associated with children's exposure to food/beverage marketing. Policy options in this area are being sought in order to reduce childhood obesity rates on a population-level. We examined the nutritional quality of foods advertised to children during their preferred television viewing in Ontario (Canada), where advertising is self-regulated by industry, and in Quebec (Canada), where a child-directed advertising ban exists. A total of 428 children aged 10-12 years completed television viewing diaries for 7 days. Thirty-two television stations were recorded simultaneously between 6 AM and midnight. A content analysis of 90 h of English Ontario, French Quebec, and English Quebec children's preferred viewing was then undertaken. A total of 429 food and beverage advertisements were analyzed and their nutritional quality was assessed. Food advertisements in the Quebec French sample were statistically significantly higher in total fat, saturated fat and protein, and lower in carbohydrates and sugar per 100 g, and as a percentage of energy than food ads in the two English samples. A statistically significantly lower percentage of the Quebec French food advertisements were classified as either high fat, sugar or sodium and a smaller proportion of food ads were classified as "less healthy" compared to the Ontario and Quebec English samples. These results suggest that the Quebec advertising ban is influencing the macronutrient profile of advertised foods viewed by French Quebec children during their preferred viewing and that their promotions are marginally healthier than that viewed by the English samples.