If patients with acromegaly remain untreated, they have a 10-year reduction in life expectancy, in particular due to cardiovascular and respiratory problems and to the increased risk of neoplasms. The standardized mortality ratio (SMR, the observed mortality divided by the expected mortality in a sex- and age-matched control population) is from 1.8 to 3.46,48,49 and 50 The most important predictive factor of mortality is the “final” posttherapeutic serum GH level.46,47,48,49 and 50 When the “final” serum GH level is <2.5 μg/L, the mortality is not significantly different from that of the general population. When the final serum GH level is >2.5 μg/L, the SMR is between 1.4 and 2, which signifies a statistically different mortality from that of the general population. This indicates that application of the more stringent definition of cure or successful outcome in acromegaly which is currently used (i.e., serum GH levels of <2.5 μg/L) is probably associated with better survival than were the criteria previously used (i.e., serum GH <5 μg/L or <10 μg/L).