Background: No data is available evaluating the difference in serum versus plasma sample assay of commonly tested parameters in the biochemistry department, where the sample processing time can be significantly reduced if plasma is used for analysis instead of conventionally used serum. Hence, this study aimed comparsion of various biochemical parameters in serum and plasma. Material and method: The comparative descriptive study was conducted in department of Biochemistry in Guru Gobind Singh Medical college and hospital, faridkot. Total 300 participants were enrolled in this study. Result; Mean age of study group the maximum number 23% of patients The were from the age group of 20-39 years. On the other hand, age-group 40-49 and 50-59 years were sharing 40% and 37% (respectively) of the total number of participants. Mean age was 35.46±8.5 years and range 20-59 years. Total numbers of participants enrolled in the study were 193 males and 107 were females, sharing a percentage 63% and 37% respectively The comparison of Rft/Lft and electrolytes from serum and plasma were performed on fully auto analyzer which show significant correlation (p< 0.05). Conclusion: It was concluded that good correlation is found between routine parameters analyzed in serum and plasma but mean difference between the two is significant so serum preferred for routine biochemical analysis.