In Italy sickle cell disease is mainly represented by sickle cell anemia (beta s/beta s) and sickle cell thalassemia (beta s/beta oth or beta s/beta+ th). Association of Hb S with other beta variants has been observed in other ethnic groups. Since some of these variants have electrophoretic mobility at alkaline pH similar to Hb S, they are frequently misinterpreted as Hb S in the homozygote state. This paper reports the first case of Hb S/Hb D-Los Angeles observed in Italy. The authors underline the need to perform accurate and specific tests in all patients with sickle cell disease and available relatives, in order to exclude combinations of Hb S with other beta hemoglobin variants.