CBS News reported that the Institute of Industry Property ruled in favor of Gradiente Electronica, which meant Apple could not use the name iPhone in Brazil.
The ruling applies to handsets only, CBS reported.
Gradiente began selling what it calls iPhones last December, years after it filed for the trademark, which Apple argued validated Gradiente's claim to the brand name.
Gradiente's product runs on an Android operating system.
Apple has settled two other lawsuits related to brand names. It settled a case with Cisco Systems, which was the original owner of the iPhone name, and also with Proview, a Chinese company that gave up the rights to the name iPad for $60 million.
The future of the name in Brazil is uncertain. A Gradiente official said last week the company was willing to discuss a settlement with Apple over the trademark.