Objective. To review the world literature regarding apical microleakage measurement techniques in endodontics. Methods. This is a narrative review that consists of reading and contrasting different sources through a search in the digital databases: PubMed, SciELO and Google Scholar. Twentyone articles were included in the literature review, selected according to the established inclusion criteria. Results. The following techniques were found: dye penetration fluid fltration, dye dissolution, bacteria and toxin infiltration method, air pressure method, electrochemical method, radioisotope method, metal solution tracers, inverse diffusion method, artificial cavities, scanning electron microscopy, transmission electron microscopy, computedmicrotomography. Conclusions. A perfect apical seal is desirable to prevent remaining bacteria and their endotoxins from reaching the root apex. Apical le...