Plasma and fractionated lipoproteins from 40 Lewis Lung Carcinoma grafted mice were tested from the first day up to the fatal issue by biochemical analyses and water suppressed 1H NMR spectroscopy. We have confirmed first, that the 1H NMR spectra of plasma lipoproteins are modified by the tumoral state and could provide a useful marker of the disease as long as they are used for individual follow-up with appropriate spectral parameters. Using fractionated lipoproteins we have demonstrated secondly, that the observed spectral modifications do not result from a specific cancer lipoprotein but from quantitatively modified ratio between Very Light Density Lipoproteins and High Density Lipoproteins.