Co-expression of T cell antigens in B-CLL has been well recognized. The commonest T cell antigen known to be expressed in B-CLL is CD5, and recent reports suggest that CD5 expression is associated with good prognosis. Expression of CD8 antigen, however, is much less common with uncertain prognostic significance. We report a case of B-CLL with aberrant CD8 expression, who had unusual disease progression with a fatal outcome.