Pulmonary hypertension (PHT) has been reported to be high among endstagerenal disease (ESRD) patients. Pulmonary hypertension (PHT) can be the result of heart, lung or systemic disorders (Archer and Rich,2000). Nitric oxide (NO) is a gaseous molecule that is produced in theendothelial cells and is involved in the regulation of tone in both thepulmonary and systemic circulations (Giaid, 1998). Impaired nitric oxideproduction and reduced sensitivity to nitric oxide have been described inpatients with CRF (Vaziri, 2001).The aim of this study is to assess the prevalence of pulmonaryhypertension among chronic kidney disease patients on conservativetreatment, and the relation between plasma nitric oxide level andpulmonary artery pressure in these patients.Our study Included 32 patients with Chronic Kidney disease (CKD)stage 3-5 on conservative treatment and 30 health subjects.We found that elevated pulmonary artery systolic pressure (PASP) inChronic Kidney disease patients on conservative treatment. Nitric Totalplasma oxide was found to be significantly lower in Chronic Kidneydisease patients on conservative treatment . Total plasma nitric oxide wasfound to be negatively correlated with PASP in highly significant relation.