Diet-induced hyperlipidaemic rabbits were given 50% ethanolic extract of Terminalia arjuna tree bark in doses of 100 mg/kg (Group B, n = 6) and 500 mg/kg (Group C, n = 6) and compared with controls (Group A). At 60 days of intervention in Groups A, B and C mean +/- S.E.M. total cholesterol was 574 +/- 61, 320 +/- 29 and 217 +/- 44 mg/dl, respectively (P < 0.01); LDL cholesterol was 493 +/- 57, 271 +/- 30 and 162 +/- 44 mg/dl (P < 0.01); HDL cholesterol was 59 +/- 7, 36 +/- 3 and 35 +/- 4 mg/dl (P = n.s.); triglyceride was 108 +/- 13, 67 +/- 6 and 101 +/- 26 mg/dl (P = n.s.); cholesterol/HDL ratio was 10.1 +/- 1.3, 9.2 +/- 1.1 and 6.1 +/- 1.0 (P = n.s.); and LDL/HDL ratio was 8.7 +/- 1.3, 7.8 +/- 1.1 and 4.5 +/- 1.0 (P < 0.01). The extract did not adversely affect biochemical tests of liver and renal function and haematological parameters.