Background: Potassium (K+) is the essential micronutrient and major intracellular fluid cation which involves in various cellular metabolism activities, maintaining fluid and electrolyte balance. Measurement of blood concentration in a medical laboratory has often encountered disturbances such as hemolysis, which may lead to the elevation in measurement and affects the medical diagnosis and treatment of the patient, conceivably fatal. Hemolysis can be decided using hemolysis index (H-index) through automation. Methods: In this study, H-index and concentration of fifty hospitalized patients (n=50) hemolysed blood samples were measured and correlated. Freezing-and-thaw method was used to hemolyse the blood samples. Different concentrations were diluted and analyzed using COBAS 8000 biochemistry analyser. Data were collected and analyzed using SPSS version 25. Results: Our findings showed significant mean differences, 0.001 (p ≤ 0.05) and strong positive linear relationship between two variables (H-index and ) (r=0.764, p ≤ 0.05). By applying calculated linear equation [y = 0.0048x + 5.146, = 0.5838], critical value of 6.0 mmol/l gives H-index of 178, H-index above 178 is suggested to be critical. Discussion and Conclusion: Concentration increases in proportion to H-index. A greater degree of hemolysis causes more ions to be released into extracellular fluid, respectively. In conclusion, when H-index less than 178 in measurement and there is no analytical significance bias generated, the result is acceptable, whilst H-index with analyte variation between clinically significant bias range can be released with a comment regarding the potential of data alteration. Meanwhile, result with H-index exceeding the cut-offs should be suppressed and recollection of sample is required.