For many cancers, adolescents and young adults (AYAs) have a poorer prognosis than pediatric patients. Our study evaluates survival outcomes of children (0‐17 years) and AYAs (18‐39 years) diagnosed with acute myeloid leukemia (AML) in the Netherlands between 1990 and 2015 (N = 2058) utilizing the population‐based Netherlands Cancer Registry, which includes information on therapy and site of primary treatment. Five‐ and 10‐year relative (disease‐specific) survival were estimated for all patients, children and AYAs. Multivariable analyses were performed using generalized linear models (excess mortality) and logistic regression (early mortality). AYAs with AML had a substantially lower 5‐ and 10‐year relative survival than children (5‐year: 43% vs 58%; 10‐year: 37% vs 51%). The gap in 5‐year relative survival was largest (nearly 20 percent‐points) in 2010 to 2015, despite survival improvements over time across all ages. The multivariable‐adjusted excess risk of dying was 60% higher in AYAs (95% CI: 37%‐86%). Early mortality (death within 30 days of diagnosis) declined over time, and did not differ between children and AYAs. In conclusion, AYAs diagnosed with AML in the Netherlands had a worse prognosis than pediatric patients. The survival gap seemed most pronounced in recent years, suggesting that improvements in care resulting in better outcome for children have not led to equal benefits for AYAs. What's new? For many cancers, children under 18 have better survival outcomes than adolescents and young adults, age 18‐39. Here, the authors evaluated long‐term survival of young people diagnosed with acute myeloid leukemia in the Netherlands. When they compared outcomes, they found that adolescents and young adults had a worse prognosis than children. Although survival has improved across all age groups, the disparity between children and adolescents and young adults has widened. Treatments that improved outcomes for children, therefore, do not appear to have benefited adolescents and young adults to the same degree.