Background: Chronic kidney disease (CKD), which is also referred to as chronic renal disease, refers to the gradual deterioration of kidney function that occurs over several months or years. Anyone whose glomerular filtration rate (GFR) has been less than 60 mL/min/1.73 m2 for at least three months is diagnosed with chronic kidney disease, regardless of whether or not there is any kidney damage present. Aim and objectives: to study the effect of chronic kidney disease on the pulmonary system, Subjects and methods: The study was performed on 40 patients with chronic kidney disease at Faculty of Medicine – Benha University , Result: There was significant differences between two groups as regard CBC, urea, creatinine, K and uric acid. There was insignificant differences between two groups as regard D dimer. There was a statically significant correlation between PE max % predictive and duration of illness and dialysis , temperature , Sat.O2, FVC ,Hb,WBCs , PLTT, urea , creatinine , INR, K, , uric acid and albumin. Conclusion: Awareness of the interrelatedness of respiratory and renal function is important in managing patients with diseases of both the lungs and the kidneys,