Two modified mapping tables that convert Abbreviated Injury Scale (AIS) 98 codes to AIS 2008 codes have been separately developed by Palmer et al. (P‐map) and Tohira et al. (T‐map). We aimed to determine which map gives the most accurate code conversion. We computed the intraclass correlation coefficients for the Injury Severity Score (ISS), the New ISS (NISS) and the Maximum AIS (MAIS) of six body regions using the mapped AIS 2008 codes and the manually determined AIS 2008 codes (gold standard). We also applied post‐hoc severity adjustment to the mapped AIS 2008 codes. The ISS and NISS based on the two maps showed substantial agreement with the gold standard. The chest region MAIS of the P‐map and the extremities region MAIS of both maps demonstrated moderate agreement with the gold standard, while the MAISs of the other regions displayed substantial agreement. The post‐hoc severity adjustment for the P‐map significantly improved the agreement for the chest region MAIS. The injury severity scores based on the two maps displayed similar agreement with the gold standard. The post‐hoc severity adjustment provided by the P‐map might be better at adjusting for severity levels than that provided by the T‐map.