Introduction: Death information plays a critical role in the adjustment of health plans, and the cause of death coding leads to organizing this information .The Purpose of this study was to review the impact of errors in the completion of death certificate on underlying the cause of death coding in Shahid Mohammadi hospital in Bandarabbas.

  Methods : This descriptive-cross sectional study was performed in the second half of 201 1 by studying the death certificates of all extinct. First, certificates were written on aside forms and residents determined the sequences of death certificates. Next, researcher recoded certificates and compared his codes with original coders. At last, researcher referred to certificates themselves to extract information about documentation errors. Data were analyzed by SPSS using descriptive statistics , chi ² test and 95percent confidence interval.

  Results : The accuracy rate of underlying the cause of death coding was 51.7percent. There was a significance between coding accuracy and major errors (P=0.001) but there was no significance between coding accuracy and minors. There was a significance between language of death certificate and occurrence of both major and minor errors(0.227and 0.006). There was also significance (0.227and 0.006). between number of lines and occurrence of both kinds of errors (0.000).

  Conclusion : the Impact of majors errors on accuracy of underlying cause of death coding has been proved. To solve this problem, physicians must be trained and the structure of death certificate must be edited.