Objectives: The present study was aimed to evaluate the anti-hyperlipidemic activity of newly synthesized tricyclic benzothieno 1, 2, 3-triazine derivatives namely CP-1 (3-(methyl)-5,6,7,8-tetrahydro,3H-benzo[4,5] thieno [2,3-d][1,2,3] triazin-4-one), CP-2 (3-(ethyl)- 5,6,7,8-tetrahydro,3H-benzo[4,5] thieno[2,3-d][1,2,3] triazin-4-one) and CP-6 (3-(2-chloro phenyl)-5,6,7,8-tetrahydro,3H-benzo[4,5] thieno [2,3-d][1,2,3] triazin-4-one) against dexamethasone and Triton WR-1339-induced hyper-lipidemia in rats. Methods: Anti-hyperlipidemic activity of the test compounds were evaluated against dexamethasone (10 mg/kg, subcutaneous [s.c.]) and Triton WR-1339 (200 mg/kg, intraperitoneal [i.p]) induced hyperlipidemia in rats. Results: Administration of single dose of Triton WR-1339 (200 mg/kg i.p) and dexamethasone (10 mg/kg s.c.) for 8 consecutive days to adult wistar rats caused severe hyperlipidemia characterized by marked increase in serum cholesterol, LDL-C, VLDL-C and triglyceride levels along with an increase in atherogenic index. Serum HDL-C levels were decreased significantly compare to normal control. Pretreatment with Atorvastatin (10 mg/kg, p.o.), CP-1 (25 & 50 mg/kg), CP-2 (25 & 50 mg/kg) and CP-6 (25 & 50mg/kg) showed significant and dose-dependent protection against dexamethasone and Triton WR-1339-induced hyperlipidemia in rats by maintaining serum total cholesterol, LDL-C, VLDL-C and HDL-C levels within the normal range. Also, a significant decrease in atherogenic index was observed. The anti-hyperlipidemic effect of CP-6 was comparable with reference standard Atorvastatin. Furthermore, CP-6 was found to be more potent than CP-1 and CP-2. Conclusion: These findings suggest that CP-1, CP-2 and CP-6 possess significant anti-hyperlipidemic activity against experimental animal models of hyperlipidemia.