Treatment with methotrexate for 1 year has been shown to delay the development of undifferentiated arthritis into rheumatoid arthritis (RA), particularly in anti-citrullinated protein antibody (ACPA)-positive patients. However, long-term results of the PROMPT study now show that this very early introduction of methotrexate does not improve long-term clinical and radiological outcomes. Progression to classifiable RA, achievement of drug-free remission and radiological progression was similar among patients in the methotrexate (n = 55) and placebo (n = 55) groups at 5 years.