Armored scales and their parasitoids were collected and identified from avocado orchards in 2 municipalities of the state of Mexico; the population fluctuation and parasitism of the 3 most abundant armored scales also were determined. The armored scales species (Hemiptera: Diaspididae) identified were Hemiberlesia cyanophylli (Signoret), Davidsonaspis aguacatae (Evans, Watson, & Miller), Diaspis nr. coccois (Lichtenstein), Hemiberlesia lataniae (Signoret), and Hemiberlesia rapax (Comstock); as well as the associated parasitoids Encarsia aurantii (Howard), Encarsia citrina (Craw), Encarsia gaonae (Myartseva & Evans), Encarsia lounsburyi (Berlese & Paoli), Aphytis proclia (Walker), Coccobius averini (Myartseva); Coccobius juliae (Myartseva), Coccobius mariae (Myartseva) (all Hymenoptera: Aphelinidae), Signiphora falcata (Woolley & Dal Molin); Signiphora fax (Girault), Signiphora flavella (Girault), Signiphora mexicana (Ashmead) (all Hymenoptera: Signiphoridae), and Plagiomerus diaspidis (Crawford) (Hymenoptera: Encyrtidae). Some species from both groups constituted new distribution or host records in Mexico. Armored scale population densities generally increased per orchard and type of avocado tree structure from Oct to Apr, depending on the phenology of the avocado trees. The percentage of parasitism and adult parasitoid emergence varied according to their armored scale host population density. Most of the parasitoids emerged from armored scales collected from branches (82), followed by armored scales collected from fruits (59), and leaves (18).