Background: The use of selective COX-2 (sCOX-2) inhibitors with acute kidney injury, salt water retention, and cardiovascular events have been correlated in subjects with normal kidney function, but sCOX-2 inhibitor use concerning the progression of chronic kidney disease (CKD) remains uncertain. Objectives: To determine the progression of renal function and electrolyte abnormalities among CKD patients after using sCOX-2 inhibitors during short-and long-term periods. Methods: The study employed a retrospective cohort design comprising all types of CKD patients with and without sCOX-2 inhibitors (celecoxib and etoricoxib). Data collected included medical data, estimated glomerular filtration rate (eGFR), and serum electrolytes at 3 and 6 months between January 2009 and January 2014. Subjects attended the outpatient clinic and were then followed up until discontinuation of the drugs at years 1 and 2 until May 2016. Results: Ninety-two CKD patients on sCOX-2 inhibitors and 92 CKD patients without sCOX-2 inhibitors were included. The sCOX-2 inhibitor group showed more decline in eGFR than the control group at 3 and 6 months of follow-up (-8.27 +/- 9.75 vs -1.64 +/- 6.05 mL/min/1.73 m(2), P< 0.001 and -12.36 +/- 6.48 vs -4.31 +/- 5.11 mL/min/1.73 m(2), P=0.001, respectively) and at 1 and 2 years of follow-up after subjects discontinued sCOX-2 (-6.84 +/- 10.34 vs -1.61 +/- 8.93 mL/min/1.73 m(2), P=0.004 and -10.26 +/- 10.19 vs -5.12 +/- 8.61 mL/min/1.73 m(2), P=0.005, respectively). In addition, the sCOX-2 inhibitor group had significantly more increased serum potassium during the study follow-up than the control group. Conclusion: The sCOX-2 inhibitors are associated with an increased risk for rapid eGFR decline and hyperkalemia in both the short term and in the long term after sCOX-2 inhibitors were terminated in the setting of a community-based CKD population. For CKD patients, these results suggest that sCOX-2 inhibitors should be closely monitored and chronic exposure to any sCOX-2 inhibitors should be avoided.