Medical coding in clinical trial research is essential for accurately documenting and categorising patient data, diagnoses, procedures, and outcomes. This process involves converting clinical information into standardised codes using systems like ICD-10, CPT, and SNOMED. Accurate coding ensures consistency, facilitates data analysis, and supports regulatory compliance. It plays a crucial role in tracking trial progress, assessing treatment efficacy, and enabling reliable data comparison across studies. By ensuring precise and uniform data representation, medical coding enhances the integrity and efficiency of clinical trial research.