Cattleya mendelii and C. quadricolor are endemic orchids from Colombia, which have been subjected to extraction from their natural environments for commercial purposes, becoming critically endangered.However, there is no sustainable management practice for the conservation of these species.The aim of this study was to establish a protocol of in vitro culture for both species.The effects of different combinations of GA 3 and NAA amending MS and KC culture media were assessed for the in vitro germination and plant growth.Plant development was assessed monthly over 120 days.A higher percentage of explant production for both species was observed with MS than KC.The higher GA 3 proportion of 1.5 μM resulted in enhanced germination, while the higher NAA concentration of 1.5 μM favored later stages of plant development.For instance, the number of roots and the length of roots and shoots were higher under incubation on MS that under KC for both species.In vitro germination for C. mendelii and for C. quadricolor was successful for their propagation and could be useful in future conservation programs for these species.