Mesenchymal stem cells (MSCs) have been able to attract a sizeable portion of the scientific community worldwide currently involved in intensive research about the unique properties of the MSCs that can be exploited for designing cell-based therapeutics for a number of otherwise-untreatable diseases. More than three decades has passed since the concept of multiple connective-tissue derivation from postnatal bone marrow-derived progenitor/stem cells originated. Although crucial leads have been provided in this field since then, significant issues relating to the experimental handling, characterization, identification, and isolation of the MSCs still remain. Such uncertainties pertaining to MSC research can greatly impact their proposed therapeutic use.