In this study, the Turkish watermelon genetic resources were collected in 2004 and morphologically characterized in 2005. The collection comprising of traditional cultivars and local accessions were collected from 15 different provinces of Southeastern Anatolia, Aegean, Marmara-Thrace, Middle Anatolia and Mediterranean regions of Turkey where local watermelon types are widely grown. A total of 134 accessions were characterized morphologically according to UPOV descriptor list for 56 qualitative characters (6 seedling, 4 plant, 11 leaf, 5 flower, 23 fruit and 7 seed) and morphologic relatedness were examined. Additionally, 22 quantitative characters were also measured. Our results indicated that the accessions studied have a great deal of variation for most of the morphological traits. The accessions were divided into five different groups according to principle component analysis. However, the geographical origin was not a great source for grouping.