RAPD markers analysis was performed to investigate genetic relatedness among nine sterile (A), maintainer lines (B), and male parents (C) of onion. Initially, 180 arbitrary decamer primers were screened; of these 20 primers were selected which yielded 812 bands, 45.34% of which were found to be polymorphic. Squared-Euclidean Distance matrix revealed a minimum genetic distance between the genotypes MS 48A and MF 65C and a maximum genetic distance between the genotypes MLT 84C and MF 65B. Cluster analysis grouped the nine onion genotypes into two major clusters. The first cluster consisted of two male sterile groups, i.e. MS-65 (Arka Lalima) and MS-48 (Arka Kirthiman) of single bulb onions. The second cluster consists of MLT (Multiplier) group. PCA re-confirmed the results of the dendrogram, revealing the precision in estimation of genetic relatedness among the genotypes tested. None of the primers produced unique banding patterns to distinguish all nine genotypes. This information about genetic relatedness among the nine genotypes would be better utilized in further onion breeding programs.