The negative symptoms of schizophrenia still cause one of the major problems in therapeutic work with schizophrenics. Although there has been great progress in the field of pharmacology for identifying effective drugs to alleviate the negative symptoms, we are still far away from having satisfactory and successful results. The purpose of the present project was to study the effects of dopamine agonists such as Bromocriptine on the negative symptoms of schizophrenia.A double-blind, cross-over controlled design was applied for this purpose. The participants were chosen on the basis of their diagnosis to prevent the effects of confounding factors. Caution was made to choose those patients who showed severe negative symptoms, but who did not have any of the following: depression, active psychosis, substance abuse, physical diseases, drug side-effects, and did not use drugs or have disorders which contraindicated the use of Bromocriptine. Out of 60 patients under treatment for schizophrenia, 14 met the above mentioned criteria, two of which refused to participate, (n=12).The 12 participants were randomly assigned to the experimental and the control groups, and were observed for 13 weeks. For 6 weeks the patients in the experimental group received 15 mg of Bromocriptine, and those in the control group received placebo. For one week, both groups received placebo (washing period),and for the final 6 weeks the two groups were crossed over, the former experimental group receiving placebo, and the former control group receiving 15 mg of Bromocriptine.For measuring the effects of the drug on the positive and negative symptoms, the PANSS which is a standardized instrument for this purpose was applied.The data was analyzed by wilcoxon, using the SPSS computer program, in two different ways. The results of the analysis showed that adding a dopamine agonist such as Bromocriptine to the drug regimen, can have significant effects on the negative symptoms of the patients with schizophrenia; Bromocriptine can not only reduce the negative symptoms of schizophrenia, but also prevent the risk of psychosis.