The Consumer Defense Foundation in Sao Paulo fined fast-food giant McDonald's 3.19 million reais ($1.77 million) for including toys in children's meals.
The organization considered that giving away toys with a "happy meal" creates eating habits harmful to youngsters' health, the official Agencia Brasil news service said.
An NGO filed a complaint last year against the company for distributing toys with meals.
In spite of that, the company has aired 18 ad campaigns since then targeting kids in which it used the enticement of toys to sell happy meals, according to the news service.
McDonald's, which can appeal the fine, argued in a press release that it complies with Brazilian law and follows precise rules of advertising self-regulation.
In 2009 Brazilian prosecutors recommended that McDonald's and other fast-food chains stop giving away toys with children's meals so as not to promote unhealthy eating habits.