Changes in membrane lipid content and composition have been repeatedly detected in experimentally induced as well as spontaneous tumors. Previous data on ganglioside analysis in human astrocytomas suggested a possible correlation between their content and pattern and the histological grading of these tumors. In our study we could definitely prove this correlation: in fact the level of malignancy, passing from grade I to grade IV, is associated with a statistically significant increase of a ganglioside identified as ganglioside GD3. Another important modification in the ganglioside pattern of human astrocytomas is the decrease in polysialylated species with increasing level of malignancy.