This nationwide population-based study assessed trends in treatment, trial participation and survival among 1833 adult patients diagnosed with acute lymphoblastic leukemia (ALL) in the Netherlands between 1989 and 2012 reported to the Netherlands Cancer Registry. Patients were categorized into four periods and five age groups (18-24, 25-39, 40-59, 60-69 and ⩾70 years). The application of allogeneic stem cell transplantation (alloSCT), particularly reduced-intensity conditioning (RIC) alloSCT, increased over time up to age 70 years. The inclusion rate in the trials was 67, 66, 55, 58 and 0% for the five age groups. Survival improved over time for patients below 70 years. Five-year relative survival in the period 2007-2012 was 75, 57, 37, 22 and 5% for the five age groups. In that same period, 5-year overall survival among patients aged 18-39 years was 68% for the chemotherapy-alone group and 66% for the alloSCT group. For patients aged 40-69 years, the corresponding estimates were 24 and 41%. Pronounced survival improvement observed among patients aged 18-39 years might mainly be explained by implementation of pediatric-based regimens since 2005, whereas among patients aged 40-69 years, increased application of RIC-alloSCT has contributed significantly to the observed improvement. Outcome of patients aged ⩾70 remains unsatisfactory, indicating a need for specific trials for the elderly.