Formal approaches to software development are techniques that aim at developing quality software by employing notations, analysis processes, etc., based on mathematical grounds. Although traditionally they aim at increasing software correctness, formal techniques have been applied to various other aspects of software quality. Moreover, while originally formal methods employed complex "heavyweight" mechanisms for analysis (often manual or semi automated), there has been progress towards embracing "lightweight", many times fully automated, analysis techniques, that broaden the adoption of formal methods in various software engineering contexts. The Latin American Workshop on Formal Methods brings together researchers working in formal methods, and related areas such as automated analysis. In particular, the workshop provides a venue for Latin American researchers working in these areas, to promote their interaction and collaboration. The workshop was held in August as a satellite event of CONCUR 2013. It took place in Buenos Aires, Argentina's capital and largest city, and one of the most interesting cultural places in South America.