Seed protein diversity of fourteen lentil cultivars grown in Turkey was studied by using sodium dodecyl sulfate polyacrylamide gel electrophoresis. A distance matrix was produced based on five polymorphic protein bands, scored for their absence as 0 and presence as 1. Seed protein distances among the cultivars ranged from 0.00 to 0.80. The dendrogram based on the distance matrix indicated two distinct clusters. The first cluster includes the cultivars Sultan 1, Meyveci 2001 and Kayi 91. The second cluster contains the cultivars Pul 11, Ozbek, Emre 20, Malazgirt 89, Ciftci, Seyran 96, AliDayi, Firat 87, Sazak, Erzurum 89 and YerliKirmizi.