Acute lymphoblastic leukemia (ALL) is a genetic disease that arises from the various recurrent genetic alterations blocking the differentiation of the precursor B-and T-cells, resulting in the aberrant proliferation and survival of immature lymphoblasts within the peripheral blood and bone marrow. T-ALL is an aggressive type of ALL, and the current treatment strategies, including the high-intensity combination chemotherapy, result in different side effects which are difficult to accept or ultimately lead to the death of patients as substantial toxicity of those chemotherapeutics is known to healthy cells alongside with the cancer cells. Therefore, there is a need to identify nontoxic, costeffective, potent, and readily available treatment options for T-ALL patients. One alternative option is the flavonoids in cancer therapeutics, which are secondary metabolites of plants mainly responsible for plants' colors and flower aromas. Luteolin is an extensively researched member of the flavonoids with anticancer properties shown in various cancer types, except for the T-ALL. This study demonstrated Luteolin's time- and dose-dependent antiproliferative, cytostatic, and apoptotic effects on T-ALL cells for the first time in the literature. Also, the macromolecular changes caused in response to Luteolin treatment in T-ALL cells were examined for the first time. As a consequence, it was found that Luteolin had antiproliferative, apoptotic, and cytostatic effects on T-ALL cells, suggesting its therapeutic potential and was demonstrated to cause an increase in the lipid-to-protein ratio and the hydrocarbon chain length of the lipid acyl chains in a dose-dependent manner on T-ALL cells.