An appreciation of the fundamental principles associated with the development of the craniofacial structures is essential for attaining competency within the fields of facial surgery, dentistry and pediatrics. The objective of this literature review was to highlight the main stages and precise time ranges of human upper lip development, as well as to elucidate the fundamental mechanisms of normal morphogenesis and possible congenital malformations. The structures of the head and neck arise from the lateral portion of the neural tube, which forms five pairs of branchial arches. Recent studies have identified various molecular pathways (including Bmp, Fgf and Shh signaling) and genetic mechanisms in human face development. Primordial structures of the upper lip begin to appear early within the 6th week of ontogenesis; their development involves a number of highly coordinated, genetically programmed ontogenetic mechanisms that include growth and expansion of the facial prominences, programmed cell death, active fusion and breakdown of the epithelial seam between the initially freely maxillary, medial nasal, and lateral nasal processes. Defects of epithelial and mesenchymal fusion during upper lip formation result in orofacial cleft. Further research should be directed to studying normal ontogenesis at the molecular and topographical levels with the determination of critical periods, time ranges and developmental stages that are sensitive to teratogens.