The therapeutic effect of crude rhubarb on intestinal permeability was investigated in septic patients. Forty septic patients were enrolled in this study and randomly divided into two groups: the crude rhubarb treatment group (n = 18) and the control group (n = 22). The same treatments were given to both groups except that the crude rhubarb treatment group was administrated with crude rhubarb powders (3 g, tid, p.o). The levels of procalcitonin, D-lactate in plasma and lactulose/mannitol (L/M) ratio in the urine were determined on the first day and the sixth day after treatment with or without crude rhubarb. There were no significant differences in procalcitonin, L/M ratio and D-lactate on the first day between the crude rhubarb treatment group and the control group (p > 0.05). However, the ratio of L/M on the sixth day for the control group was 0.167 +/- 0.036, while that of the crude rhubarb treatment group was 0.062 +/- 0.013 (p < 0.05). Moreover, the levels of procalcitonin and D-lactate in the crude rhubarb treatment group were obviously lower than those in the control group on the sixth day (procalcitonin: 4.11 +/- 1.40 microg/L vs. 2.21 +/- 0.61 mug/L; D-lactate: 0.24 +/- 0.06 ng/L vs. 0.09 +/- 0.03 ng/L, p < 0.05, both). These data confirmed that crude rhubarb's effects on septic patients of ameliorating intestinal permeability.