Background: Methotrexate (MTX) is the first-line drug in the treatment of rheumatoid arthritis (RA) and the most commonly prescribed disease modifying antirheumatic drug. Moreover, it is also used as an adjuvant drug in patients under biologic therapies, enhancing the efficacy of biologic agents. Objectives: To review the literature and update the Portuguese recommendations for the use of MTX in rheumatic disea...