The intra-puparial development of the black soldier-fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), was studied based on 125 pupae under controlled conditions in laboratory. The 6^th instar larvae were reared until they stopped feeding, and the pre-pupae were separated according to the reduction in larval length and degree of pigmentation and sclerotization of the cuticle. The pupal stage lasted eight days (192 hours). The process of pupation (larva/pupa apolysis) occurred in the first six hours, extroversion of the head and thoracic appendages took place between the ninth and 21^st hours, and the pharate appeared 21 hours after completing pupation. After pupariation, four morphological phases of intra-puparial development were observed and described.