Background: Potassium abnormalities are common in chronic kidney disease patients due to low glomerular filtration rate (GFR) and tubular abnormalities. Electrolyte imbalance across the membrane potential can manifest as ECG changes. It is found that patients with hyperkalemia in chronic kidney disease had ECG changes. Therefore, we conducted this study to investigate the association between serum potassium levels and electrocardiogram of hyperkalemia patients in stage 5 non dialysis chronic kidney disease. Methods: A cross-sectional study conducted at Wahidin Sudirohusodo Hospital, Makassar, Indonesia in January 2024. We included all patients aged ≥18 years with stage 5 chronic kidney disease who had never undergone hemodialysis. Then, the serum potassium level and electrocardiogram examination were performed. The data then analyzed with Chi-Square.Results: This study consisted of 101 subjects who were mostly male (53.5%) and aged ≤60 years (71.3%). Elevated serum potassium levels were found in 59.4% subjects. ECG abnormalities were found in 45.5% and most ECG abnormalities were tall T (58.2%). We found a significant association between hyperkalemia and ECG abnormalities (p<0.001). We also found a significant association between hyperkalemia and the appearance of tall T (p<0.001).Conclusion: We found significant association between hyperkalemia with ECG abnormalities, especially tall T, in non dialysis stage five chronic kidney disease patient. ECG abnormalities were mostly found in severe hyperkalemia.