Studies of therapy-related AML (t-AML) are usually performed in selected cohorts and reliable incidence rates are lacking. In this study, we characterized, defined the incidence over time and studied prognostic implications in all t-AML patients diagnosed in Sweden between 1997 and 2015. Data were retrieved from nationwide population-based registries. In total, 6779 AML patients were included in the study, of which 686 (10%) had t-AML. The median age for t-AML was 71 years and 392 (57%) patients were females. During the study period, the incidence of t-AML almost doubled with a yearly increase in t-AML of 4.5% (CI 2.8% - 6.2%), which contributed significantly to the general increase in AML incidence over the study period. t-AML solidly constituted over 10% of all AML cases during the later study period. Primary diagnoses with the largest increase in incidence and decrease in mortality rate during the study period (i.e. breast and prostate cancer) contributed significantly to the increased incidence of t-AML. In multivariable analysis, t-AML was associated with poorer outcome in cytogenetically intermediate and adverse risk but t-AML had no significant impact on outcome in favorable risk AML, including core binding leukemias, APL and AML with mutated NPM1 without FLT3-ITD. We conclude that t-AML displays a strong increase in incidence over time and that t-AML constitutes a successively larger proportion of the AML patients. Furthermore, we conclude that t-AML confer a poor prognosis in cytogenetically intermediate and adverse risk, but not in favorable risk AML.