Background: Cor-pulmonale complicates 2-6/1000 of patients with chronic obstructivepulmonary disease (COPD).The early diagnosis of RV dysfunction secondary to pulmonaryhypertension can reduce morbidity and mortality.Aim of Work: The objective of our study is to assess the usefulness of tissue Dopplerimaging (TDI) in evaluation of RV function in patients with COPD in comparison to firstpass radionuclide angiography (FPRNA) which is the gold standard method. Another aim is to determine the relationship between lateral tricuspid annulus TDI parameters andPASP as estimated by continuous wave Doppler in patients with COPD.Patients and Methods: Thirty patients with COPD diagnosed by history, clinicalexamination, CXR, laboratory findings (ABG, CBC), 12-lead ECG, TDI (to measure MPI,Sm, SmVTI, Em/Am), FPRNA (to measure RV EF)Results: Based on the nuclear study (FPRNA) our 30 pts divided to 17pts (56.7%) withRVEF > 45% (55.2±1.4) and 13 pts (43.3%) with RVEF < 45% (37.7±6.2). From the 1st17 pts, 15 pts showed by TDI, MPI < 0.7 (0.56±0.09) and Sm ≥ 12 cm/s (15.3±1.7 cm/s)and 2 pts showed MPI ≥ 0.7 Sm < 12 cm/s. From the 13 pts with RVEF < 45% (37.7±6.2)12 pts exhibited by TTI MPI ≥ 0.7 and Sm < 12cm/s (mean 0.83±0.05 and 9.7±1.07 cm/srespectively) and one pt exhibited normal MPI and Sm. Based on the relationship betweenPASP measured by continuous Doppler tricuspid valve and lateral tricuspid annularvelocities Sm (13.7±2.9cm/s), SmVTI (2.2±0.7), Em/Am (0.6±0.2). The correlation was r= -0.61 for Sm, r = -0.72 for SmVTI and r = -0.60 for Em/Am. The results of TDI andFPRNA in evaluation of RV function compared to clinical signs of cor-pulmonale wereP-value 0.001and 0.01 respectively. Also in our study we compared between diameter ofRV measured by conventional echocardiography and result of TDI in evaluation of RVfunction where p-value = 0.01.Conclusion: There is significant correlation between TDI and FPRNA in the ability todetect RV dysfunction in COPD pts by a sensitivity 92.3%, specificity 88.2% and P-value= 0.001. There is a good negative correlation between PSAP measured by continuousDoppler and later tricuspid annular velocity with P-value 0.001. There is a significantcorrelation between result of TDI and FPRNA in evaluation of RV function compared toclinical data signs of cor-pulmonale where P-value = 0.001 and 0.01 respectively. Alsothere is a significant correlation between results of TDI in evaluation of RV function anddiameter of RV measured by conventional echocardiography where P-value = 0.01. TDI isconsidered a new, easy, bedside and less expensive technique in assessment of RVEF.