The short-term impact of famines on death and disease is well documented, but estimating their potential long-term impact is difficult. We used the setting of the man-made Ukrainian Holodomor famine of 1932-1933 to examine the relation between prenatal famine and adult type 2 diabetes mellitus (T2DM). This ecological study included 128,225 T2DM cases diagnosed from 2000 to 2008 among 10,186,016 male and female Ukrainians born from 1930 to 1938. Individuals who were born in the first half-year of 1934, and hence exposed in early gestation to the mid-1933 peak famine period, had a greater than twofold likelihood of T2DM compared with that of unexposed controls. There was a dose-response relationship between severity of famine exposure and increase in adult T2DM risk.