The study of crop genetic diversity has received attention in recent decades to develop new varieties adapted to harsh environmental conditions. Pea (Pisum sativum L.) is one of the main sources of legumes due to its higher protein content. In the present investigation, 25 accessions of Turkish and Tunisian peas were characterized by fifteen ISSR markers in order to preserve this germplasm and develop new highperformance varieties. Means of diversity indices, Polymorphism information content (PIC), resolving power, marker index, major allele frequency and Shannon index were 0.70, 5.56, 3.20, 0.89 and 0.35, respectively. The analysis revealed a higher polymorphism (84.15%). The coefficient of similarity Jaccard varied from 0.45 to 1 exhibiting a greater genetic variety. The patterns detected by the cluster analysis, divided the 25 pea genotypes into three main groups. These findings were in agreement with the population structure which divided accessions into three main populations. Therefore, this paper has clearly shown the usefulness of the ISSR markers to provide a great degree of polymorphism for peas. The information collected from this work can help pea breeders to implement a selection program that improves the distribution of this crop in Turkey and in the arid regions of Southern Tunisia.