Geometry optimization of gemcitabine was carried out by DFT with B3LYP/6-311++G(d,p) level in the gas phase. Chemical activity (electronegativity, electrophilicity, hardness, chemical softness and chemical potential) was predicted with the help of HOMO-LUMO energy values. Experimental FT-IR was recorded and computed values are also analyzed using the same level of DFT. A complete vibrational spectrum was made to analyze the potential energy distribution (PED). Stability of the molecule arising from the hyper-conjugative interaction was analyzed by the natural bond orbital (NBO). The molecular electrostatic potential map was used to detect the possible electrophilic and nucleophilic sites in the molecule. Nonisothermal decomposition of gemcitabine was carried out in an air atmosphere. The two decomposition steps of the molecule were analyzed kinetically by linear and nonlinear methods for elucidation of the kinetic triplet (E_a, ln A and f(α)) of the decomposition processes. Powder X-ray diffraction indicated that gemcitabine crystallizes in the monoclinic system (SG P2/m). Molecular docking studies were also described.