In this study, the structural, spectroscopic, thermochemical, and toxicological properties of 3-(2-furyl)-1H-pyrazole-5-carboxylic acid (FPCA) were systematically investigated using density functional theory (DFT). The optimized molecular geometry, frontier molecular orbitals, vibrational frequencies, and electronic transitions were analyzed to elucidate the electronic structure and reactivity of FPCA. Thermochemical parameters, including molar thermal energy, heat capacity, and entropy, were calculated as a function of temperature, and the corresponding thermochemistry surface maps (TCSM) were constructed to visualize the thermal behavior of the molecule. Toxicological predictions were carried out using computational models to assess organ toxicity, mutagenicity, and ecotoxicity, indicating moderate hepatotoxic, neurotoxic, and nephrotoxic potentials, while several nuclear receptor and stress-response pathways remained inactive. Integrating quantum chemical calculations within silico toxicity analysis provides comprehensive insights into the potential biomedical and environmental implications of FPCA.