In Japan stomach cancer remains the leading cause of cancer‐related mortality. We analysed the annual mortality rate of stomach cancer in relation to age, gender and life expectancy in Japan between 1970 and 1995. The adjusted stomach cancer‐related mortality rates decreased from 88.9 in 1970 to 45.4 per 100 000 in 1995 in males and from 46.5 to 18.5 per 100 000 in females. The male–female ratio for stomach cancer‐related mortality in all ages was 1.9–2.5 during this 25‐year period, and the mortality rate was higher in females than in males at young age. The negative contribution to life expectancy for stomach cancer in males was 0.65 years and 0.42 years in females, which is consistent with a higher mortality rate in males. This negative contribution was 41.8% of total cancer in 1970 and 39.4% in 1995 in males and 34.4% and 16.0%, respectively, in females. Our results demonstrated the need to take into consideration the characteristics of stomach cancer in young women and the effects of ageing when designing programmes aimed at prevention and control of this malignancy.