In 1992 a pioneer collaborative study showed that methotrexate (M) is effective in paediatric
reumatology. Now we know that 60% of IJA patients who do not respond to non-steroidal
antinflammatory drugs respond to M, that the best response is observed in pauciarticular
forms evolving in poliarticular as well as in poliarticular forms at onset. Side effects are
mainly gastroenteric, but they rarely cause withdrawal of treatment. No gonadal damage
and no increased risk of cancer have been observed. The administration of folinic acid reduces
the likelihood of side effects. Oral M is as effective as intramuscular M. M should be
considered the first choice long-acting drug for all forms of IJA.