The MTX has a place of choice in the treatment of the AJI with good observance and the absence of grave side effects. In a retrospective study, 14 cases of AJI having benefited from a treatment by MTX were included in the study. Answer to the treatment was estimated at the 6-th month on the criteria of RINTO. The group included in the therapeutic evaluation, is formed by 10 boys and by 4 girls. The average age of the beginning of the disease is of 6 years (2 - 11). The shape of the beginning is systematic in 7 cases and polyarticular in 5 cases and oligoarticular in 2 cases.. The average duration of the treatment by MTX is of 36 months (9 - 66). Answer to the MTX in the 6-th month was noted in 7 cases, under a MTX's average dose of 7, 14mg / m2 / week. Unwanted effects were observed in 7 cases and have not in any case led to the stop of the treatment