Lagenaria siceraria (Molina) Standl in the Cucurbitaceae family is a large, pubescent, climbing, or trailing herb cultivated throughout India and the tropical regions of the world. Phytochemical investigation of the methanol extract obtained from the fruits of the plant L. siceraria showed a positive Liebermann-Burchard test for sterols. The white sterol crystals or phytosterols from the methanol extract were isolated for the first time and identified as a mixture of four sterols, including fucosterol (1), racemosol (2), stigmasterol (3), and stigmasta-7,22-dien-$3{eta}$,$4{eta}$-diol (4). These compounds were identified by spectroscopic evidence including FTIR, $^1H$-NMR, MS, and GC. The white sterol crystals, which are the mixture of four sterols, were evaluated for antihyperlipidemic activity in Wistar rats. The blood samples were collected from the retro-orbital plexus and serum was separated and analyzed for lipid profiles. These sterol crystals (30 mg/kg) showed significant reductions in lipid profiles which included cholesterol, triglycerides, LDL and VLDL. In addition, a significant increase in HDL cholesterol observed, which is a good cholesterol that protects hearts from coronary artery diseases. These sterol crystals or phytosterols can be used as an antihyperlipidemic agent to treat the hyperlipidemic.