Field trials were conducted to study the dominant piercing-sucking insect species infesting potato plants in Dakahlia Governorate. The obtained results indicated that there were six piercing-sucking insects attacking potato plants and the dominant piercing-sucking insects were Myzus persicae (Sulker); Aphis gossypii Glover; Empouasca descipiens Polai. and Bemisia tabaci (Gennadius) during the two years of study. Data cleared that M. persicae and A. gossypii had one peak in each potato plantation and E. descipiens recorded two peaks in summer plantation, in the meanwhile three peaks in winter plantation during the two years of investigation. B. tabaci had three peaks in summer and winter plantation during the period of study.  The obtained results revealed that there were four predators belonging to Family Coccinellidae namely: Hippodamia trideciapunctata L., Coccinella undecimpunctata L., Chilomenes propinqua isis (Mulsant) and Chilomenes propinqua nilotica(Mulsant), and one predator from family Chrysopidae, namely Chrysoperla carnea (Steph.) was recorded. It can be stated that most dominant species were H. tridecimpunctata and C. undecimpunctata.