BACKGROUND: In sub-Saharan Africa umbilical cord blood may be a useful source of blood for transfusion. Before clinical trials, evidence is needed that cord blood donations, which vary greatly in volume, can be collected and stored into a fixed volume of anticoagulant-preservative solution obviating the need for prestorage processing. STUDY DESIGN AND METHODS: Twenty-four umbilical cord whole blood (UC-WB) donations were collected into 21 mL of CPDA-1 and refrigerated for 35 days. The Kenya Blood Transfusion Service provided 12 adult-donated whole blood (AD-WB) controls. Supernatant hemoglobin (Hb) and potassium were assayed at 7-day intervals. RESULTS: UC-WB red blood cell hemolysis and potassium loss increased throughout storage but did not differ significantly with cord blood volume. Hemolysis rates did not differ significantly between UC-WB and AD-WB but UC-WB potassium loss was slightly but significantly greater than AD-WB on Days 2, 7, and 14 (p < 0.05). In the AD-WB controls, eight were low volume (<405 mL), two had total Hb of less than 45 g, and two showed hemolysis greater than 0.8% by Day 28. CONCLUSION: Variable volumes of UC-WB can be stored for 35 days without prestorage processing and further work into its suitability for transfusion to children is justified. The quality of conventional AD-WB is a concern and needs further evaluation.