General Background The pre-analytical stage represents a critical phase within clinical laboratory testing sequences because it involves initial procedures largely reliant on manual handling and personnel precision. Specific Background Implementation of Internal Quality Improvement (IQI) serves as the primary evaluation tool to analyze pre-analytical factors affecting clinical laboratory test results. Knowledge Gap Although overall pre-analytical quality appears optimal, recurring human-factor errors during critical operational points remain inadequately mitigated across routine workflows. Aims This study evaluates pre-analytical variables influencing laboratory test accuracy and assesses the role of educational interventions in mitigating human-induced errors. Results Findings indicate that while internal quality performance generally ranges from good to very good, critical vulnerabilities persist during patient identification, phlebotomy execution, and anticoagulant-to-specimen volume ratios. Novelty This literature review synthesizes multi-year publication data from 2015 to 2015 to map recurrent pre-analytical discrepancies and evaluate targeted educational impacts. Implications Systematic staff education and standardized compliance significantly enhance procedural reliability and clinical diagnostic safety. Key Findings Highlights Pre-analytical error rates are predominantly driven by manual handling vulnerabilities during patient identification and sample collection, Phlebotomy technique discrepancies and sample-to-anticoagulant ratio deviations significantly compromise test result accuracy, Structured educational interventions effectively improve staff compliance and reduce human-factor errors. Keywords Pre-Analytical, Internal Quality Improvement, Clinical Laboratory, Laboratory Errors, Quality Control