Gadolinium (Gd), a rare earth element extensively utilized in medical imaging and industrial applications, is increasingly present in aquatic ecosystems. This study investigates tissue-specific accumulation and antioxidant responses in Procambarus clarkii after 14-day exposure to environmentally relevant Gd concentrations (0.1, 1, 10, and 100 µg/L). Gd accumulation occurred in the gills and hepatopancreas at higher concentrations (10 and 100 µg/L), while levels in muscle remained below quantifiable limits. Antioxidant responses varied across tissues, and non-metric multidimensional scaling (NMDS) revealed no consistent pattern, indicating limited activation likely linked to low tissue burdens and brief exposure. However, superoxide dismutase (SOD) activity significantly increased in the gills and hepatopancreas at higher Gd concentrations. In contrast, glutathione peroxidase (GPx) activity showed inconsistent trends, while glutathione S-transferase (GST) activity was elevated in hepatppancreas and muscle only at 0.1 μg/L. Lipid peroxidation was most pronounced in the gills. The Integrative Biomarker Response-Threshold (IBR-T) index indicated low-dose effects consistent with hormesis, reflecting biologically relevant changes at minimal Gd concentrations. Overall, P. clarkii exhibited tissue-dependent Gd accumulation and oxidative responses, though biomarker activation patterns were inconsistent.