Methotrexate (MTX) is the most commonly used disease modifying antirheumatic drug in juvenile idiopathic arthritis (JIA). We aimed to define predictor factors for response to MTX in Turkish children with oligo- and polyarticular JIA. We reviewed the medical files of 59 oligo- and 57 polyarticular JIA patients seen in the clinic between May 2008 and May 2013 and who received MTX for >= 6 months. MTX responders were defined as having no/low disease activity according to juvenile arthritis disease activity score 71 (JADAS71) at 6 months after MTX initiation. Median age at JIA diagnosis/MTX initiation was 70/78 months. Involvement of the small or upper extremity joints at disease diagnosis and MTX initiation was more frequent; antinuclear antibody (ANA) positivity was less frequent; acute phase reactants, JADAS71 at MTX initiation, and the frequency of polyarticular subtype were higher in MTX non-responders. In multiple logistic regression, oligoarticular JIA subtype and ANA positivity were independent predictors of MTX response.