Twenty three hydatidiform moles (HMs) were studied using the techniques of "RFLPs" employing a minisatellite deoxyribonucleic acid probe. Among the 23 HMs, 17 were homozygous types resulting from a duplicated haploid sperm, and two were heterozygous types resulting from fertilization two independent sperms (dispermy). It was revealed that the four histopathologically diagnosed complete HMs (CHMs) were partial HMs (PHMs) with one maternal and 2 paternal chromosome contribution (diandry) or two maternal and 1 paternal alleles (digyny). The locus specific minisatellite probes were useful in classifying CHM into heterozygous and homozygous types as well as in diagnosing PHM. One heterozygous (50%) and 5 homozygous (29.4%) CHMs, and one PHM (25%) progressed to persistent gestational trophoblastic disease (p > 0.5).