Mortality data from official sources, and survival data from population-based cancer registries, are used for the estimation of incidence and prevalence of stomach cancer. Time trends of morbidity, survival, and mortality during the period 1970-90 are presented and analyzed. Incidence rates were decreasing during the considered period, but the rate of decrease was slowing down during the last decade. Almost stable rates, and even slightly increasing for women, were estimated for the youngest cohorts. Relative survival for stomach cancer was higher for women and for young ages; it was associated positively with period of diagnosis, and presented a significant South-North geographic gradient. Prevalence was estimated as decreasing during the period 1970-80, but increasing during the successive decade, due to both better survival and population aging. Projection of stomach cancer morbidity and mortality to the year 2000 showed that the disease should still be considered in Italy as a major public health problem.