Objective To evaluate the antihyperglycemic potential of Tamarix aphylla (T. aphylla) leaves in STZ–NIC induced diabetes in Wister Albino rats. Methods Acute toxicity study was done to check the toxicity of T. aphylla (L. Karst) methanol extract. T. aphylla leaves extract was administered intraperitoneally (100 mg, 250 mg and 400 mg/kg body weight per day) to diabetic Wister rats for 21 days. The various parameters were studied including fasting blood glucose levels, haemoglobin and glycosylated haemoglobin. Results The treatment groups with the extract at three dose levels expressively abridged the intensities of blood glucose and Glycosylated Haemoglobin. The earlier detected reduced level of plasma haemoglobin of the diabetic rats was raised to near normalcy with treatment of extract. Conclusions The results of the current study confirm that the leaves extract of T. aphylla are nontoxic and have antidiabetic nature.