The current study is conducted to observe the differences in the level of low molecular weight proteins in the sera of patients with leukaemia in comparison to healthy subjects (control group). The sera of patients with leukaemia showed 15 peaks in the densitometric curve in comparison to the seven peaks of the controls. The peaks in the experimental samples that coincide with those in the control were of 134.14, 113.15, 76.06, 63.25, 48.07, 22.85 and 16.47 kDa molecular weights, respectively. Most of the new peaks appeared between the proteins of molecular weight 36–29 kDa in the experimental groups. Mean density of the 134.14 kDa protein band showed an increase in the protein in experimental groups I and II only whereas 113.15 and 22.85 kDa protein were increased in all experimental groups of patients with leukaemia. The expression of 76.06 and 63.25 kDa protein fraction was downregulated in the patients with leukaemia. A decline in the level of the protein of 48.07 kDa was observed in patients with leukaemia except in Group I. Unlike the other protein fractions, the level of the protein of 16.47 kDa was significantly (p < 0.05) increased with a maximum density in Group II. Intergroup (experimental) comparison revealed an increasing pattern of 95.44 and 89.21 kDa with maximum level in Group III sera. However, the protein fractions of 38.07 and 34.94 kDa varied in the serum with maximum density in Group IV. Protein fractions of 32.92 and 31.24 kDa were expressed in all age groups of patients with leukaemia with a maximum density in Group III whereas the percentage densities of 14.42 and 13.56 kDa protein were quite different. This preliminary study will provide a basis to study the role of different proteins in patients with leukaemia.