The study of pests is important to assure production and health of avocado (Lauraceae) plants. Whiteflies (Hemiptera: Aleyrodidae) are a secondary pest of the crop, but are associated with reduction in tree vigor and yield. Three species of whiteflies associated with avocado were identified. Specimens were collected in the State of Morelos at altitudes of 1,736 m (“Tlayacapan” orchard, municipality of Tlayacapan), 1,934 m (“Tlalnepantla B” orchard, municipality of Tlalnepantla), and 2,230 m (“Tlalnepantla A” orchard, municipality of Tlalnepantla). Fourth-instar nymphs were mounted in Canada balsam. Morphological identification was based on illustrations by Carapia et al. (2003), Iaccarino et al. (2011), and Hodges and Evans (2005) and corroborated by the specialist of Aleyrodidae taxonomy, Dr. Vicente Emilio Carapia Ruiz. Molecular analysis was done using the COI gene. Sequences obtained, edited, and assembled were compared with those of the National Center for Biotechnology Information (NCBI) database. Tetraleurodes perseae Nakahara, Paraleyrodes minei Iaccarino, and Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) were identified. The first two were collected on avocado trees, and the third was found in weeds associated with an avocado orchard. For P. minei, there was 98% similarity with a record for the subfamily Aleurodicinae and 82% with the species Paraleyrodes bondari. T. vaporariorum had 96% similarity with 13 previous records of the same species.