Eight ALL patients displaying a CD7+, Tdt+, CD10-, T MoAbs-, myeloid MoAbs-, AP+ phenotype are described. Some patients showed well-known risk factors such as cytogenetic abnormalities, high WBC count, mediastinal mass, and/or organomegalies. The clinical behaviour was very poor and only one patient is in CR and off therapy. Therefore such a pre-T phenotype, although sometimes associated with the other risk factors, could be considered a poor prognosis phenotype.