Background Stomach cancer is the second commonest cause of mortality from cancer worldwide; in Iran it is the commonest. Geographical variation in the incidence of stomach cancer is reported. Data describing the geographical distribution of disease in Iran are lacking. The aim of this study was to examine geographical variation in stomach cancer mortality in Iran.

Methods We used the Iranian National Causes of Death Registry and estimated age-standardised mortality rates (ASMR) of stomach cancer in 29 provinces, using the age distribution of the world standard population, stratified by sex and residential area (rural/urban).

Results ASMRs of stomach cancer were 15 per 100 000 in men and 8 per 100 000 in women. The highest and lowest mortality rates were observed in Kordestan (ASMR=29.1 per 100 000) and Hormozgan (ASMR=5.0 per 100 000) provinces in the north-western and southern Iran, respectively. The mortality rates were approximately twice as high in men and rural residents as women and urban residents respectively.

Conclusions The incidence of stomach cancer in Iran is a high with evidence of regional variation. The substantial variation in stomach cancer mortality rates between northern and southern Iran warrants further investigation. The results of this study can be used for resource allocation and to inform the designing of appropriate gastric cancer control programs in Iran.