The aim of this work was to use IR spectroscopy to investigate the spectroscopic changes in lymphocytic leukemia compared with normal blood. This can lead to suggest the IR spectroscopy as a diagnosis technique for leukemia. Four blood samples were collected from patients in Khartoum city diagnosed by histopathology as Acute lymphocytic leukemia (ALL), Chronic lymphocytic leukemia (CLL), Acute myeloid leukemia (AML) and Chronic myeloid leukemia (CML). The IR spectra of leukemia samples were compared with that of normal blood. Considerable numbers of peaks were recorded in the range between 400 and 4000 cm-1. The IR spectra of the samples showed characteristic peaks in the spectral range between 900 and 3450 cm-1. The locations of these peaks in the spectrum of normal blood sample and the spectra of leukemia blood samples are the same with respect to the positions while significant differences in their intensities were recorded. The comparison of these peaks showed significant differences in the intensities and in the intensity ratios between leukemia samples and normal blood. The results proved that IR spectroscopy can be used for diagnosis of lymphoid leukemia.