A cytotaxonomic study in the Himalayan orchids was undertaken to delineate the evolutionary trends and to unravel problems of phylogeny and taxonomy. Cytological observations on 20 species from northwest Himalayan region are reported. On the basis of secondary association among bivalents and chromosome numbers in multiples, it has been suggested that all the species ofHabenariainvestigated by us were hexaploid. The formation of bivalent chains and occurrence of dicentric bridges and fragments inNeottia listeroideswere attributed respectively to translocations and inversions at meiosis. InEpipactis belleporine, in addition to four pollen grains in a tetrad, one to two « sporads» were noted. A high proportion of taxa investigated were found to be polyploid. A number of genera had species with aneuploid numbers.