Background. The reliability of harvesting neuronal progenitor cells (NPCs) from the adult human neocortex has not been established, with respect to preparing autologous cell cultures for transplantation in stroke and traumatic brain injured patients. Method. Enriched NPC cultures have been generated from nonneurogenic regions of the adult rodent brain by buoyancy-dependent fractionation, but the feasibility of using such a method to isolate NPCs from the adult human cortex has not been reported previously. To determine if a starter population of human adult cortical NPCs could be isolated for in vitro expansion using this method, tissue samples from five patients undergoing cortical resection for either epilepsy or trauma were assayed. Findings. Cultured cells generated from all patients predominately expressed both the NPC marker nestin and neuron-specific β-tubulin III. The presence of NPCs was verified by in vitro BrdU/β-tubulin III co-labeling and increasing β-tubulin expression in differentiating conditions. Despite the formation of aggregates in monolayer culture, cell proliferation as measured by BrdU incorporation was not as prevalent as that reported from rodent cultures generated by this protocol. Conclusions. NPCs isolated from the adult human neocortex using this method expressed β-tubulin III in larger percentages than has been previously reported for NPCs isolated using other methods. As such, these data suggest the possibility of culturing dividing neuroblasts from the adult neocortex for further manipulation as transplantable cells.