In Timor-Leste, many adults learn to read and write in a multilingual context. The official languages are Tetum and Portuguese, 15 regional languages are being further developed and Bahasa Indonesia and English are accepted as working languages. Most literacy programmes take place in Tetum, the lingua franca, and often regional languages are used for explanation and instruction. For many people Tetum is a second language. Speaking and understanding Tetum facilitates the process of learning to read and write. Alongside regional languages and other languages, Tetum is also widely used in various domains of daily life, and in reading and writing. Although multilingualism is a fact inside and outside literacy classes in Timor-Leste, a focus on the acquisition and use of Tetum seems advantageous in both settings. The main aim of this article is to explore the adult literacy education landscape in the context of the post-independence multilingual language policy of Timor-Leste and to investigate the influence of Tetum proficiency and other teacher and learner characteristics on the development of literacy abilities. (Contains 18 notes, 3 figures and 5 tables.)