Crambe is a promising crop since the species of this genus is used in industry, medicine and as vegetable. For the present investigation, 32 germplasm accessions representing to 7 Crambe taxa were collected from different regions of Turkey. These collections included 17 of Crambe orientalis var. orientalis, 2 of C. orientalis var. sulphurea, 1 of C. orientalis var. dasycarpa, 1 of C. grandiflora, 4 of C. tataria var. tataria, 2 of C. tataria var. aspera and 5 of C maritima. Clustering analysis and 2-dimensional principal coordinates analysis was used to represent the genetic relations among taxa by using ISSR data. Clustering analysis clearly distinguished the species groups. Two major clusters were formed; first consisted of C. orientalis and C. grandiflora taxa, the second consisted of C. tataria and C maritima taxa. Principal coordinates analysis showed 4 species groups: C. orientalis, C. grandiflora, C. tataria and C. maritima. C. grandiflora placed closer to C. orientalis accessions and C. maritima accessions placed closer to C tataria group. The purpose of the present investigation was to understand the genetic affinities among wild relatives of Crambe and to provide information on genetic relationship of the different species of the genus for their efficient use in future breeding programs especially in Turkey and environs. The findings on genetic affinities from this study also provide important clues for solving some taxonomical conflicts of the genus. (C) 2015 Elsevier B.V. All rights reserved.