The diversity of Cicadellidae (Hemiptera: Auchenorrhyncha) associated with the maize crop in Tucumán province (Argentina) was studied. Samplings in two different sown dates, optimal and late, took place during the 2004-2005 and 2005-2006 growing seasons. The cicadellids were sampled from the coleoptile emergence to the vegetative stage V10. Thirty five species, belonging to six subfamilies, were identified, of which fifteen species were new records to Tucumán province, and nine were registered for the first time inhabiting maize agro-ecosystems. The most abundant and frequent species was Dalbulus maidis (DeLong & Wolcott), followed by Agalliana ensigera Oman and Chlorotettix fraterculus (Berg), which were present in all 44 samples. The diversity indices obtained were H’=1.75 and D=0.47 for the optimal sown date, and H’=0.46 and D=1.52 for the late one, being Dalbulus maidis the species with highest relative importance in both sown dates. Curves of seasonal abundance for the five most common species were showed.