In most cases you WILL need a visa stamp in your passport in order to enter Brazil. Please feel free to use the “Need a Visa” checker on this page.
Once you check you can get all the information needed to apply for your Brazilian visa. As a matter of reciprocity a Brazilian Tourist VISA is required for American citizens visiting Brazil in addition to having a valid passport to enter Brazil. The Brazilian Consulate will permanently stamp your VISA to the inside of your passport and will thus need to physically have your passport for processing.
If you are not an American or Canadian citizen, you need to check to see if you need a VISA to enter Brazil for tourism purposes.
Identify your consular jurisdiction, which is determined by your place of residence, and always check with your consulate for specific information about hours of operation, processing time, and payment methods. Or better yet, CIBT can do it all for you!