Current studies suggest a derangement of the cholesterol homeostasis in certain types of leukaemia. The low serum cholesterol levels observed in patients with AML have been related to the tumoral mass and to the disease activity. Only a few studies have taken into consideration a possible change of the serum lipids in ALL. The aim of this study was to evaluate a possible prognostic significance of serum levels of total cholesterol (TC), triglycerides, HDL-C, LDL-C, VLDL-C, apolipoproteins A1 and B and lipoprotein (a), investigated in 10 newly diagnosed ALL patients before and after induction treatment. At diagnosis all these parameters were not significantly different in our patients vs control group except cholesterol and HDL-C levels, which were significantly lower. After the induction treatment, we found a significant increase of HDL-C and Apo A1 values only in those patients that achieved a complete remission. These results support the idea that some serum lipids, such as HDL-C and Apo A1, may have a role as early and reliable markers of the effectiveness of chemotherapy.