Abstract: Traditional medicines are administered mostly as decoctions. The mechanism of the LDL-cholesterol lowering effect of Terminalia littoralis decoction used in ethno-medicine is hypothesized. The decoction prepared from fallen dry leaves of T. littoralis was screened for its relevant phytochemical contents. The pH, concentration and fibre content were of the decoction determined. A feeding study using the decoction as the only source of fluid was carried out for 35 days using albino rates of the Wistar strain. Anthropometric measurements and serological examinations were also carried out. Hypothetical deductions were based on the presence of phytochemical and biochemical constituents with reported pharmacological activities in relation to pharmacological outcome. The decoction did not significantly (p>0.05) affect the liver function indices. It however significantly (p<0.05) increased body weight and conversion of feed mass to body mass but reduced serum LDL cholesterol concentration and LDL-cholesterol/ HDL-cholesterol ratio. The hypothesized mechanisms were that decoction’s phytosterols competitively inhibited uptake of dietary cholesterol by intestinal cells and HMG-CoA reductase activity, the fibre content reduced enterohepatic bile acid cycle, the catechins increased LDL receptor activity and the tannin, flavonoid and saponin prevented the oxidation of LDL. In conclusion, the phytochemical and biochemical constituents of the Terminalia littoralis decoction lowered LDL-cholesterol through a combination of different biochemical mechanisms.