This paper revisits Maspero’s (1912) insights about the Vietnamese tone system and its link with consonant types. H. Maspero noted structural similarities between the tone systems of Vietnamese and Tai; he projected these tone systems into the indefinite past, and concluded (against Przyluski) that Vietnamese belonged to the same language family as Siamese. The present article shows that tones developed in Vietnamese from a non-tonal proto-language, as they also did in Chinese, Tai, and Miao-Yao (Hmong-Mien). Correspondences between initial voicing and tone register are illustrated by data from Vietnamese, Chinese and Tai, while the relationship between laryngeal codas and tone contours is established through a comparison of Vietnamese with other Mon-Khmer languages. This brings out the main mechanisms involved in East Asian tonogenesis. [This is a translation of the article originally published as: De l’origine des tons en vietnamien, Journal Asiatique 242: 69-82 (1954).]