The human umbilical cord (hUC) is a source of adult tissue-derived mesenchymal stem cells (MSCs). A pulsed low-intensity ultrasound (PLIUS) method is described for increasing the yield of MSCs from whole hUC without enzymatic digestion or growth factor supplementation. Analysis of the immunophenotype of cells and a differentiation study were performed to show the compatibility of MSCs. The mean number of cells recovered from primocultures of hUC was 6 x 10(5) cells/cm. PLIUS resulted in a 3.3-fold increase in MSC yield at passage 0. PLIUS exposure increases the yield of hUC-MSCs by promoting release and enhancing proliferation.