Peru, since it is established within the Pacific Ring of Fire, is considered a country with a high frequency of earthquakes. Various studies indicate that seismic coupling occurs off the coast. This, added to the scarcity of economic means to hire professional advice when designing and constructing the building, generates the inappropriate use of technical building standards. The objective of this study was to estimate levels of seismic vulnerability for existing constructions in the south-east area within the district of Lambayeque, located in the northern Peruvian coast. To achieve this, the Italian method of the vulnerability index was used, evaluating 3,054 buildings belonging to 4 types: (1) adobe buildings, (2) unconfined masonry, (3) confined masonry, and (4) reinforced concrete. Of the buildings analyzed, 15.62% has a low vulnerability level, 62.25% has a medium vulnerability level, and 22.13% presents a high vulnerability. In addition, a thematic map was made with the Geographic Information System, what expresses its seismic vulnerability by levels whose identification is made through a color scale. As a complement, a Soil Mechanics Study was prepared, obtaining allowable load capacities of the soil between 0.64 kg/cm2 and 1.00 kg/cm2. © 2023, Escuela Politecnica Nacional. All rights reserved.