Hypertension is one of the common complication after kidney transplantation due to various etiology. Hypertension causes a accelerated atherosclorsis after transplantation and is a major factor for cardiovascular morbidity and mortality and chronic allograft failure. The aim of this study is evaluation of prevalence and effect of common risk factor before and after transplantation on post transplant hypertension. All of the patients had visited one or two monthly in first year after transplantation and history and phyisical examination and neccessary laboratory measurments were done. Blood presure equal or more than or every degree of blood presure with concomitant use of antihypertensive drug was the definition of hypertension. Correlation of risk factors include age and gender of donor and recipients, recipient weight, hypertriglyceridemia, hypercholestremia, diabetes and ciggaret smoking before and after transplantation and past history of hypertention and allograft function with hypertesion were studied. 207 patients arrived in study that 70.5 percent of them were male and others were female. In three months after transplantion 73.4 percent, in six months 76.5 percent and in twelve months 84.5 percent of the patients were hypertensive. In these time intervals there isn’t significant statistical correlation between age and gender of donors and recipients, recipient weight, history of diabetes, hypertriglyceridemia and ciggaret smoking before and after and hypercholesteremia before transplantation with hypertension after transplantation. Hypercholesteremia in sixth and twelveth month, history of hypertension befor transplantation in twelveth month and function of allograft had significant statistical correlation with hypertension after transplantation. This study revealed that hypertension after transplantation has a high prevalence and history of hypertension, function of allograft and hypercholesteremia after transplantation are risk factors. According to this high prevalence and effects of hypertension on cardiovascular morbidity and mortality and chronic allograft failure, it is advised that blood pressure must be meassured exactly in follow up period and hypertension should be aggressively managed by nonpharmacologic measurs and minimization of doses of steroids and cyclosporin and pharmacologic therapy.