Alpha blockers are characterize as one of the most therapies that used for treatment of several condition such as Raynaud's disease, hypertension, scleroderma , and one of the most treatments for treated continuing pelvic pain syndrome- continuing prostatitis and also be used to treat anxiety and panic disorder such as generalized anxiety, posttraumatic stress disorder (Raskind, et al.,2003) . This study was conducted at the laboratory of department of biology, faculty of science/university of Kufa , 40 male rats that was used. The present study was conducted to investigate the effect of Prazosin hydrochloride on some organs in male rats (Rattus norvegicus), after administration of prazosin hydrochloride at three doses (25,50,75) mg/kg b.wt. for eight-weeks, prazosin revealed significant decreased at (p ˂0.05) the hemoglobin concentration, red blood cell account, packed cell volume , and erythropoietin hormone but a significant increased at (P˂0.05) in the levels of erythrocyte sedimentation rate of the blood, when compred with control group,the levels of HDL showed significant increment at (P˂0.05) in group that gives low dose (50 and 75)mg/kg b.wt. when compared with control, but significant decline at (P˂0.05) in the levels of very low density lipoprotein in group that gives low dose of prazosin (25)mg/kg b.wt. when equaled with control group, the levels of LDL and VLDL revealed significant decreased at (P˂0.05) in groups that gives moderate and high doses.