Because of a lack of written language, only two accounts of Incan Religion by Native American authors are known to exist. Both authors wrote in the second decade of the 17th century, in a mixture of Spanish and native languages. Neither of the authors was ethnically Incan, but both could trace their ancestry to tribes that had been conquered by the Incas.

"Letter to a King", by Felipe Guaman Poma de Ayala, is a 1200-page letter addressed to the King of Spain. After being lost for nearly 300 years it was discovered in the royal library of Copenhagen, in 1906.

The second work is "An Account of the Antiquities of Peru", by Joan de Santacruz Pachacuti Yamqui Salcamaygua, much of which is totally incomprehensible, since the author was only semiliterate.