The role of Fourier Transform Infra-Red (FTIR) spectroscopy in the clinical analysis has increased tremendously in the recent past, due to the development of sophisticated instruments and efficient data evaluation software. The application of FTIR spectroscopy in the analysis of blood is highly promising. This technique has many advantages over the regular clinical analysis like very minimum sample requirement, avoid of costly disposables, minimum manpower requirement etc. Blood is the preferred indicator of the pathophysiological condition of a living system. Cancer is a dreadful disease and continuous research is going on for the early detection, treatment and monitoring. Cancer in general is associated with the proliferation of the abnormal cells without control. Out of the many forms of cancer, leukemia is cancer of the blood or bone marrow characterized by an abnormal increase of white blood cells, which are also referred to as leukocytes. Leukemia is clinically and pathologically split into its acute and chronic form, and is categorized into four major types namely Acute Lymphocytic Leukemia (ALL), Acute Myelogenous Leukemia (AML), Chronic Lymphocytic Leukemia (CLL) and Chronic Myelogenous Leukemia (CML). ALL is a cancer of the white blood cells that normally fight infections. ALL accounts for the majority of the childhood leukemia that affects the young children between 3 and 12 years. ALL may also occur in adults. Studies indicate that leukemia is not inherited or contagious. Several factors are suspected, although scientists are unable to pinpoint the exact cause. No specific sets of preventions are available. The present study aims to characterize the blood samples of ALL patients with the healthy subjects using Fourier Transform Infra-Red (FTIR) spectroscopic technique. The FTIR spectra of ALL and healthy blood samples have been recorded. It is observed that the general shape of the spectra is similar but there is considerable change in the absorption of the characteristic peaks. As a measure to characterize the healthy and leukemia blood, the intensity ratio calculation have been carried out among some of the specific absorption peaks for both healthy and diseased samples. It is observed that the values are different in both the samples. Statistical analysis is performed to find whether the absorption ratios differ in the healthy and diseased groups employing Analysis of Variance (ANOVA) and independent t-test. Thus the role of FTIR spectroscopy in the clinical analysis of blood samples has been established both qualitatively and quantitatively.