Rapid user-friendly ABO-Rh blood typing kits (Eldon Home Kit 2511, ABO-Rh Combination Blood Typing Experiment Kit) were evaluated to determine their accuracy when used under simulated military field conditions and after long-term storage at various temperatures and humidities. Rates of positive tests between control groups, experimental groups, and industry standards were measured and analyzed using the Fisher's exact chi-square method to identify significant differences (p < or = 0.05). When Eldon Home Kits 2511 were used in various operational conditions, the results were comparable to those obtained with the control group and with the industry standard. The performance of the ABO-Rh Combination Blood Typing Experiment Kit was adversely affected by prolonged storage in temperatures above 37 degrees C. The diagnostic performance of commercial blood typing kits varies according to product and environmental storage conditions.