Four DNA probes (L754, p99-6, pERT87-l and pERT87-15) from the short arm of the human X chromosome were studied in two European (English and Spanish) and two Asiatic Indian (Maratha and Parsi) populations. All four RFLPs showed conclusive heterogeneity among the four populations. Nei’s genetic distance (d) matrix shows an affinity between the Parsis and the population from southern Europe. There is an interesting suggestion of a west to east cline for allele *2 detected by probe L754. Genetic heterogeneity found for the X-linked RFLPs prove that these markers are a useful tool for population genetics studie