Nanostructured materials, defined by their distinctive physicochemical properties at the nanometer scale, facilitate the innovation of sophisticated applications through their inherent size-dependent phenomena and surface characteristics. In this study, we explore the synthesis of ZnSe nanostructures with distinct spherical and flower-like morphologies by varying the concentration of Ethylenediamine tetraacetic acid (EDTA). Our findings reveal that higher concentrations of EDTA facilitate flower-like morphologies, which provide a large surface area desired for gas sensing applications. Herein, the as-synthesized ZnSe nanostructures were applied for ammonia (NH3) sensing at room temperature at different concentrations to evaluate their performance. The results obtained indicate that ZnSe nanostructures with flower-like morphology exhibit superior sensing capabilities, demonstrating a good response (ΔR/Rair)% of 71 % compared to the 61 % response observed for spherical ZnSe nanostructures for 20 ppm NH3 gas, measured at room temperature. Additionally, the flower-like ZnSe nanostructures show significantly enhanced response and recovery times, demonstrating their potential as efficient materials for NH3 detection at room temperature.