The incidence of hepatitis B surface antigen (HBs Ag, Australia antigen) has been determined in three communities residing in an endemic malarial region in Western Maharashtra. A high incidence (5.92%) is found in the Marathas, a socially well-placed community, as compared to Nava-Buddhas (2.62%) and scheduled castes (1.63%) which are socially low-placed communities. A higher incidence (8.91 %) among the Maratha females is a surprising observation as the males have been shown to be predominant among HBs Ag carriers in most world populations. A positive association of HBs Ag and the anthropometric traits, skinfold thickness of biceps and triceps, has been observed in the present study. The results demonstrate that other factor(s) (e.g. immunological) besides malarial infection may be involved in the maintenance of a high HBs Ag frequency in Western Maharashtra.