The Song Ma structural zone or the Song Ma antilinorium is a structural unit occupying the southwestern part of the Northwest Vietnam structural block. Lying in the space between the Red River and Song Ma faults in the northeast and southwest, respectively, the complexity in geological structure and strongest seismic activity in the territory of Vietnam are the characteristics of this block. The Red River fault is considered the boundary between the South China terrane and the Indochina terrane in many publications. The Song Ma fault is recognized as the boundary between the Northwest block and the Truong Son structural block, both of which are in the Indochina terrane. Different petrologic research results have also recognized that the Song Ma fault is the collision boundary between the Indochina terrane and the South China terrane during the period of the Palaeotethys Ocean closure. As the study area is located not far from the Tibetan Plateau, its tectonic features have been strongly affected by the northwards collision of the Indian plate with the Asian plate since the mid-Tertiary. Consequently, large-scale strike-slip movements occurred along major faults in the Indochina terrane and adjacent areas. Such tectonic activities certainly leave traces in the environment of the Earth’s crustal structure. Therefore, studies on the structure of the Earth’s crust play crucial roles in better understanding the history of tectonic evolution and the laws of mineral resource distribution and in assessing and predicting the potential of geological hazards, including earthquakes. This paper presents a picture of the tectonic, neotectonic and deep crustal structures in the northwestern region of Vietnam based on recent research results, in which the neotectonic structure of the Song Ma zone is presented in more detail.