Cardiovascular diseases, including sudden cardiac death, are the leading cause of death in hemodialysis (HD) patients. A prolonged QT interval on the electrocardiogram (ECG) is a risk factor for sudden cardiac death in HD patients. Previous studies show a correlation between years of dialysis and Qtc prolongation. The aim of this cross-sectional study was to assess the prolonged Qtc interval as well as the associated electrolytes imbalances in long- term hemodialysis patients in Ibn Sina Hospital. It is an institution-based cross-sectional study, with total coverage sampling of the population. Our results illustrated that most of our participants were either 20-40 years old or 40 – 60 years old with a male predominance of approximately 68%. The association between Qtc prolongation and years of dialysis was nonsignificant (P value 0.611) in our study. When comparing between Qtc before and after the dialysis, a significant correlation (P value 0.002) was noted, which provoked the hypothesis that the dialysis affects the Qtc whilst the patient is undergoing the dialysis. Moreover, we found a significant correlation between magnesium (P value 0.009) and calcium (P value 0.044) levels with QT prolongation, potassium levels, on the other hand, showed a non-significant association (P value 0.283). In conclusion, the comparison between the Qtc before and after the patients underwent dialysis showed a significant correlation.