The article deals with the letters in Portuguese Aljamía (Portuguese texts in the Arabic alphabet script) insufficiently explored. Unlike Spanish Aljamiado, on which there is an extensive literature, including fiction, only eight manuscripts are known in Portuguese Aljamía. Six of them are letters to the King of Portugal from his subjects in Morocco. The texts allow us to make observations about the personality of the author as well as some features of the early 16-th century Portuguese language.