We herein demonstrate the biogenic nanoarchitechtonics of silver nanoparticles template over chitosan/starch mixed hydrogel having excellent reducing ability. The two biopolymers also had the capacity to stabilize as-synthesized Ag NPs. Physicochemical and structural features of the nanocomposite biomaterial was assessed by several techniques like FT-IR, SEM, TEM, EDX and XRD. TEM study revealed the mean diameter of the spherical shaped Ag NPs/CS-Starch material was in the range of 5-15 nm. Thereafter, the Ag NPs/CS-Starch bio-composite material was exploited in the study of cytotoxicity and anti-leukemia effects against diverse leukemia cell lines like acute myeloid leukemia (32D-FLT3-ITD and Human HL-60/vcr), acute lymphoblastic leukemia (MOLT-3 and TALL-104), and acute T cell leukemia (Jurkat, Clone E6-1 and J.RT3-T3.5) in situ. Interestingly, the nano-drug could resist significantly against those cell lines in a time and concentration-dependent manner, assessed by MTT method. The corresponding IC50 values of the bio-composite were 203, 301, 250, 227, 102, and 193 µg/mL respectively against the cell lines. Furthermore, antioxidant potential of the material was investigated by DPPH radical scavenging method. A significantly high IC50 value suggested the high antioxidant capacity of Ag NPs/CS-Starch nanomaterial.