The bus link from Curitiba to Foz do Iguaçu is very handy for those trying to approach Iguaçu Falls from the south region of Brazil. The bus company Catarinense runs a service between both cities. On its website you can check schedules and prices.
At the time of publishing this entry, there are between 8 and 9 daily buses (changes according to the day of the week). The trip lasts 11 hours and there are two types of buses, the convencional, costing R$90,63 one way, and the leito (bed), costing R$181,27 one way. On the company’s website you can check how many seats are still available for each service.
At the entry Iguazu Falls you will find the general information on the falls published here at the Brazil Travel Blog.