Background: The preanalytical phase is critical in laboratory testing, accounting for 46-68.2% of errors. One key factor affecting serum electrolyte levels is the serum clot contact time, which is the time between blood collection and separation of serum. This study evaluates the effect of delayed centrifugation and analysis on sodium, potassium, and chloride stability Objectives: To evaluate time lag between centrifugation and sample analysis on stability of sodium, potassium and chloride in serum. Methods: Fifty serum samples from healthy individuals were collected and analysed at the Infosys Central Laboratory. One set of samples was processed after 30minutes, while the other was kept at room temperature for 3 hours before processing. Sodium, potassium, and chloride concentrations were measured using ion-selective electrodes. Statistical analysis: The quantitative variables were expressed as mean and standard deviation. The difference in the mean values between the two groups was assessed using paired T -test and p -value of less than 0.05 was considered significant. Results: Results showed that delayed processing led to a significant reduction in sodium (p=0.001) and potassium (p=0.001) concentrations, while chloride levels remained relatively stable. Sodium levels decreased from 138±3.5mmol/L to 135.4±19mmol/L, and potassium levels dropped from 4.1±0.9mmol/L to 3.8±1.2mmol/L after 3 hours. Conclusion: The measurement of electrolytes is important for the treatment of critically ill patients. The serum clot contact time can affect the stability of electrolytes, like sodium and potassium showing a decreasing trend.