The transition from gel separator serum tubes to gel separator lithium heparinized plasma (LIH) tubes in the clinical laboratory showed favorable outcomes across various parameters according to the study findings. Most notably, the performance of clinical chemistry and immunoassay tests remained largely unaffected, with LIH tubes generally yielding comparable results to serum tubes, albeit with some analytes exhibiting total error values surpassing allowable limits. However, alternative error thresholds were identified, suggesting LIH tubes could be reliably substituted for serum tubes in most tests, except for lactate dehydrogenase (LDH). Additionally, LIH tubes led to improvements in sample quality, as evidenced by reduced aspiration errors and lower hemolysis index values, indicating enhanced sample integrity compared to serum tubes. Moreover, the transition to LIH tubes resulted in decreased turnaround time (TAT), particularly notable in the emergency laboratory setting, suggesting enhanced efficiency in sample processing and analysis. Overall, these findings underscore the potential benefits of LIH tubes in clinical laboratory settings, highlighting their role in optimizing healthcare delivery and resource utilization.