Introduction:Accurate medical diagnosis is an important issue for an appropriate treatment.the aim of this study was to compare clinical diagnosis and autopsy findings in patinents who died in university hospital in thehran.

Method:In this study, the data were collected in two part.medical records and autopsy findings od 4641 dead case,who were referd for postmortem examination to determine the cause of death,were extracted from 4671 yearle dead one files ina hospital.first part of information included demographic data (age,sex),clinical records of hospitalized patients and the first clinical diagnosis and cause of death by the physician .the second part was releted to autopsy findings(both pathology and serology)and definit cause of death.

Findings :Postmortem examination revealed acceptabele clinicali diagnosed cause of death in 47.40 %is incorrect  in internal medicin and in 1.85%of cases ,the cause of death was incorrect in nurosurjery medicine.

Discussion:considering the low rate of correct clinical diagnosis of cause of death in study,post-mortem examination remains a valuable source of patinent information.it is recommended to design a process to inform hospital physicians about the final cause of death.it may improve the management of hospitalized patients based on better diagnosis in similar situations.