Chronic lymphocytic leukaemia follows an extremely variable clinical course with overall survival times ranging from months to decades, so there is a need to identify markers that may help to refine outcome prediction for these individuals. One of the most important molecular genetics parameters defining pathogenic and prognostic subgroups of Chronic lymphocytic leukaemia is the mutation status of the IgVH genes. CD38 expression has demonstrated a highly predictive prognostic value and can be used as a convenient and accurate predictor of IgVH gene mutational status. However, because IgVH gene mutational status assay is characterized by its technical complexity, high cost and needs for high level of expertise while CD38 percent expression can be determined more conveniently, rapidly and cheaper than IgVH gene mutational status, it offer the possibility of a substitute for IgVH gene mutations analysis. Moreover it may be the preferred adjunct to the current staging systems. Indeed, the results of this simple test should enable physicians to predict with considerable accuracy whether a patient is likely to have a favorable or unfavorable clinical course.