Water soluble dinickel(II) complexes [Ni2(L)21–2](NO3)4 (1–2), where L1–2 are triazole based dinucleating ligands, were synthesized and characterized. The DNA binding, protein binding, DNA hydrolysis and anticancer properties were investigated. The interactions of complexes 1 and 2 with calf thymus DNA were studied by spectroscopic techniques, including absorption and fluorescence spectroscopy. The DNA binding constant values of the complexes 1 and 2 were found to be 2.36 × 105 and 4.87 × 105 M−1 and the binding affinities are in the following order: 2 > 1. Both the dinickel(II) complexes 1 and 2, promoted the hydrolytic cleavage of plasmid pBR322 DNA under both anaerobic and aerobic conditions. Kinetic data for DNA hydrolysis promoted by 1 and 2 under physiological conditions give the observed rate constants (kobs) of 5.05 ± 0.2 and 5.65 ± 0.1 h−1, respectively, which shows 108-fold rate acceleration over the uncatalyzed reaction of ds-DNA. Meanwhile, the interactions of the complex with BSA have also been studied by spectroscopy. Both the complexes 1 and 2 display strong binding propensity and the binding constant (Kb), number of binding sites (n) were obtained are 0.71 × 106 [1.47] and 5.62 × 106 [1.98] M−1, respectively. The complexes 1 and 2 also promoted the apoptosis against human carcinoma (HeLa, and BeWo) cancer cells. Cytotoxicity of the complexes was further confirmed by lactate dehydrogenase enzyme level in cancer cell lysate and content media.