BACKGROUND Recently, insoluble fibre from carob pulp has been found to affect blood lipids in animals in a similar manner as soluble dietary fibre. OBJECTIVE To investigate whether a carob pulp preparation containing high amounts of insoluble fibre has a beneficial effect on serum cholesterol in humans. METHODS Volunteers (n = 58) with hypercholesterolemia were recruited to participate in a randomised, double- blind, placebo-controlled and parallel arm clinical study with a 6 week intervention phase. All participants consumed daily both, bread (two servings) and a fruitbar (one serving) either with (n = 29) or without (n = 29) a total amount of 15 g/d of a carob pulp preparation (carob fibre). Serum concentrations of total, LDL and HDL cholesterol and triglycerides were assessed at baseline and after week 4 and 6. RESULTS The consumption of carob fibre reduced LDL cholesterol by 10.5 +/- 2.2% (p = 0.010). The LDL:HDL cholesterol ratio was marginally decreased by 7.9 +/- 2.2 % in the carob fibre group compared to the placebo group (p = 0.058). Carob fibre consumption also lowered triglycerides in females by 11.3 +/- 4.5% (p = 0.030). Lipid lowering effects were more pronounced in females than in males. CONCLUSIONS Daily consumption of food products enriched with carob fibre shows beneficial effects on human blood lipid profile and may be effective in prevention and treatment of hypercholesterolemia.