Diabetes Mellitus (DM) is among the most common metabolic disorders worldwide. Leaves of Capparis cartilaginea are used in folk medicine to treat diabetes in parts of Yemen. The current study aimed to investigate the antioxidant and antidiabetic effects of C. cartilaginea leaf extract. The antioxidant activity of the extract was determined using a 2.2 – diphenyl -1- picrylhydrazyl (DPPH) free radical scavenging assay. Experimental diabetes was induced in rats by alloxan (200 mg/kg), and animals with fasting blood glucose levels>200 mg/dL were considered diabetic. On day 14 post-treatment with the plant extract, body weight, fasting blood glucose, high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, and triglyceride (TG) levels were determined for serum samples. The in vitro α-amylase inhibition assay was performed using an α-amylase-based kit. The leaf extract exhibited a pronounced antioxidant effect as evidenced by an IC50 value of 187.36 µg/ml. The C. cartilaginea-treated animal groups showed a significant reduction in blood glucose levels compared to day one of treatment (P < 0.05). The extract at a dose of 200 mg/kg caused a significant decrease in the levels of LDL, cholesterol, and TG, and induced an increase in HDL (P < 0.05-0.01). The plant extract exhibited modest α-amylase inhibition with an IC 50 value of 861.3 μg/mL. The results provide evidence that C. cartilaginea may be a promising adjunct therapeutic tool for the management of diabetes and its associated hyperlipidemic complications.