Alhagi pseudoalhagi has been traditionally used as laxative since far long ago. However there is little information based on scientific methodology in this regard. In order to assess the possible laxative and prokinetic effects of the water extract of Alhagi pseudoalhagi, all rats were divided into test and control groups and they were gavaged with the drug or placebo, respectively. The number, weight and water percentage of feces were studied up to 24h. In order to assess the possible drug effects on intestinal secretion or osmotic infiltration of fluids into the gut lumen, the jejunum in anesthetized rats (n=5; thiopental sodium: 50mg/Kg) was randomly divided into 4cm segments and 0.5ml of water extract of Alhagi pseudoalhagi, lactulose (as positive control) or placebo (as negative control) was injected in each segment. The volume of contents in each segment was measured after 1h. In order to assess the gastrointestinal transit time, rats were deprived from food and were gavaged with either the extract or placebo (twice with 12h interval). Thirty minutes following the last medication, all rats were gavaged with phenol red and methyl cellulose (1.5ml). Test and control rats, in groups of 3, were sacrificed at times 30 minutes, 1, 2 and 4 hour(s). The amounts of phenol red in various parts of the gastrointestinal tract were measured. Water extract of Alhagi pseudoalhagi significantly increased feces number and its percentage of water, but had no effects on the transit time of intestinal ingesta but significantly delays cecum emptying in rats. The volume of the contents in jejunum segments had significantly increased with the extract or lactulose compared to placebo. Water extract of Alhagi pseudoalhagi apparently exerts its laxative effects via osmotic infiltration of fluids into the intestine or by increasing intestinal secretions.