Many studies have been done on the hypocholesterolaemic effect of probiotic yoghurt. The results, however, are not conclusive. The aim of the present study was to test the effect of probiotic and conventional yoghurt on the lipid profile in women. In a randomised trial, ninety female volunteers aged 19-49 years were assigned to three groups. Subjects consumed daily 300 g probiotic yoghurt containing Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 or 300 g conventional yoghurt or no yoghurt for 6 weeks. Fasting blood samples, 3 d dietary records and anthropometric measurements were collected at baseline (T1), end of week 3 (T2) and end of week 6 (T3). Lipid profile parameters were determined by enzymic methods. Results showed no significant difference in lipid profile within any group throughout the study. Comparing mean differences (T1 - T3) among the three groups showed: no difference in TAG and LDL-cholesterol, a decrease in cholesterol in both conventional (P < 0.05) and probiotic yoghurt groups (P < 0.005) compared with the control group, a decrease in total:HDL-cholesterol ratio for conventional (P < 0.05) and probiotic yoghurt groups (P < 0.001) compared with the control group, and an increase in HDL-cholesterol in the probiotic yoghurt group (P < 0.05) compared with the control group. Positive changes in lipid profile were observed in both yoghurt groups. Any added effect, therefore, is due to the consumption of fermented milk products.