The antihyperlipidemic activity of Spirulina platensis (family: Oscillatoriacae, cynobacteria/blue green algae) was evaluated in isoproterenol-induced hyperlipidemic rats. In the present study, Spirulina platensis powder suspended in water was administered orally to rats for 21 days at the dose of 450 mg/kg/day followed by subcutaneous administration of isoproterenol (200 mg/kg/day for 2 days). Isoproterenol, a synthetic catecholamine and β-adrenergic agonist has reported to cause oxidative stress with subsequent increase in serum lipid profile after subcutaneous administration. The clinical biochemistry parameters like serum cholesterol, triglycerides, HDL-cholesterol, atherogenic index, VLDL and LDL cholesterol of the rats were determined for the evaluation of antihyperlipidemic activity of Spirulina platensis. The minimum alteration in clinical biochemistry parameters were observed in Spirulina platensis treated animals as compared to control animals indicating its antihyperlipidemic potential.