Acute myeloid leukaemia (AML) is a cancer that impacts hematopoietic tissues, such as the lymphatic system and bone marrow. Conventional chemotherapy with a single drug induces complete remission in about 40% of cases, while combination chemotherapy can achieve over 50% remission. Despite advancements, long-term, free from cancer survival is accomplished in only 25% to 50% of patients. This study investigates the impact of tocotrienols (T3), including the tocotrienol-rich fraction (TRF), delta-T3 (δT3) and gamma-T3 (γT3), on the percentage of living cells of three human AML cell lines (THP-1, HL-60 and Kasumi 6), both in the presence and absence of cytarabine. A water-soluble tetrazolium (WST) cell proliferation kit was used to assess cell viability, while caspase-related apoptosis pathways were studied using caspase 3, 8 and 9 ELISA kits and gene expression analysis through quantitative polymerase chain reaction (qPCR). TRF significantly inhibited proliferation (p<0.05) in all AML cell lines, with the greatest effect seen in Kasumi 6 cells, followed by HL-60 and THP-1. Caspase 3, 8 and 9 activities increased in AML cells treated with T3 and gene expression analysis revealed a down-regulation of API5 and up-regulation of MIG6. These findings suggest that T3 may exert anti-proliferative effects on AML cells through caspase-mediated apoptosis pathways.