The genetic diversity of 20 cabbage (Brassica oleracea var. capitata, including sub.var. alba and rubra) cultivars and landraces from the Gene bank of Crop Research Institute was estimated using amplified fragment length polymorphism (AFLP) marker technology. Two cultivars of Brassica pekinensis (syn. Brassica rapa var. pekinensis) were used as outliers in the study. Thirty AFLP primer combinations produced a total of 1084 fragments. A total of 806 fragments, 364 (45%) of them polymorphic, were found across 20 Brassica oleracea var. capitata accessions. The accessions were clustered into two main groups. Special subgroups, reflecting place of origin, were observed within these groups. Ten selective primer pairs were found to be most informative because each of these uniquely identified all of the accessions used. Furthermore, two accessions of Brassica pekinensis were clearly differentiated from the Brassica oleracea var. capitata accessions. AFLP is an efficient tool for determination of genetic diversity of cabbage gene bank accessions.