BACKGROUND: Little information is available on the influence of the storage conditions on the results of hemoglobin A2 (HbA2) and F (HbF) testing. METHODS: The stability of HbA2 and HbF was assessed on stored whole blood samples tested immediately after collection and after one week of storage at either + 4 degrees C or - 80 degrees C. RESULTS: An excellent correlation was observed between fresh specimens and those stored at either + 4 degrees C (HbA2: r = 0.994; p < 0.001 and HbF: r = 0.999; p < 0.001) or - 80 degrees C (HbA2: r = 0.995; p < 0.001 and HbF: r = 0.999; p < 0.001). The mean biases from the reference fresh specimens were very modest for samples stored at + 4 degrees C (HbA2: -0.06%; HbF: 0.02%;) and - 80 degrees C (HbA2: - 0.06%; HbF: 0.05%). CONCLUSIONS: The results of our investigation demonstrate that whole blood specimens for HbA2 and HbF testing can be stored at + 4 degrees C or - 80 degrees C for up to one week.