Introduction: In this study, validity, completeness, and timeliness of coding in Iran, Tehran, and Shahid Beheshti medical universities were compared.Methods: This is a descriptive-comparative study conducted in the first half of 2007. Research population included medical records of discharged patients of all medical universities located in Tehran, namely Iran (10 hospitals), Tehran (9 hospitals) and Shahid Beheshti (10 hospitals) in the first half of 2006. Data were collected by filling a checklist to determine the rate of validity, completeness, and timeliness of coding. Data analysis was done using descriptive statistics of SPSS and Excel.Results: The validity of clinical coding in Iran, Tehran and Shahid Beheshti medical sciences universities or main diagnosis were 82.2%, 79.46%, 85.05%, for other diagnosis were 80.04%, 75.04%, 89.06%, for main procedure were 85.32%, 80.67%, 85.43%, and for other procedure were 51.86%, 84.80%, 91.3% respectively. The rate of completeness of coding in the above universities for main diagnosis were 93.06%, 96.91%, 97.96%, for other diagnosis were 88.08%, 90.76%, 95.02%, for main procedure were 96.7%, 94%, 98.93% and for other procedures were 93.85%, 97.35%, 95.65% respectively. Among the 33 mentioned hospitals, only 2 of the hospitals of Shahid Beheshti University complied with timeliness of coding. Conclusion: Although completeness of coding has improved in Iran, its validity has not been improved and has some problems. In addition, the timeliness of coding of the majority of hospitals was considerably different from the World Health Organization standards. Thus, essential attempts are necessary for
improving coding quality in these scopes.