The objective of this work was to investigate the hypolipidemic effects of an ethanolic extract of quinoa seeds (QSEE) in countering hyperlipidemia induced by Triton X-100 (T. X-100) rats. The study assessed alterations in growth performance and several biochemical parameters. Forty clinically healthy male Albino rats were equally divided into four groups: control animals; hyperlipidemic animals treated with a single intraperitoneal injection of T. X-100 on day 21; rats administered QSEE for 40 days; and rats receiving a combination of both treatments. Gas chromatography-mass spectrometry (GC-MS) analysis was used to characterize the chemical composition of QSEE before the experiment. Serum samples were collected for measurement of liver, kidney, and pancreatic function; antioxidant markers; and leptin and adiponectin hormone levels. Treatment of hyperlipidemic rats by QSEE reduced lipid profile values with hepato-renal protective effects, reduced lipid peroxidation, increased antioxidant activity, improved growth performance, and normalized leptin and adiponectin hormone levels in comparison with hyperlipidemic animals. QSEE displays powerful hypolipidemic activity associated with its content of biologically active constituents as confirmed by GC-MS analysis.