The fact of Argentina being one of the first countries to legalize gay marriage has been studied all over the world. A not-so-mentioned cause is that, according to survey data, discriminatory attitudes towards homosexual people decreased noticeable in Argentina since the restoration of democracy in 1983. The evolution of these attitudes, considered as a key indicator of the value of tolerance in any society, suggests that at least some central components of political culture may change as a product of democratic exercise and not only of economic modernization. The article also revises the attitudes towards people suffering from AIDS and people with criminal records.