To analyse the level of consistency and updating of the information on pregnancy and lactation provided by patient information leaflets (PILs) of the antirheumatic drugs approved in Argentina. Inconsistencies between the 2016 EULAR Task Force recommendations on the use of anti-rheumatic drugs during pregnancy and lactation and the information provided by PILs of the same drugs approved in Argentina were analysed along with inconsistencies within the PILs of different registered trademarks of these drugs. Eighty-eight PILs of 32 drugs were analysed. Out of the 88 PILs, 50% presented information inconsistencies as to pregnancy. Medications comprised in this group were: hydroxychloroquine, sulfasalazine, azathioprine, tacrolimus, cyclosporine, NSAIDs (during the first two trimesters), celecoxib, some glucocorticoids, colchicine, and some anti-TNF drugs (etanercept, adalimumab and infliximab) during part of the pregnancy. As for lactation, 56% had information inconsistencies. Medications encompassed in this group were: hydroxychloroquine, chloroquine, sulfasalazine, azathioprine, tacrolimus, cyclosporine, NSAIDs, celecoxib, meprednisone, prednisone, colchicine, and anti-TNF drugs. Out of 17 drugs that had more than one registered trademark, information inconsistencies on pregnancy were found in the PILs of sulfasalazine, diclofenac, ibuprofen and methylprednisolone. Concerning lactation, inconsistencies were present in the PILs of hydroxychloroquine, sulfasalazine, diclofenac, ibuprofen, meprednisone, and colchicine. At least half of the PILs of anti-rheumatic drugs analysed in this study had information inconsistencies on pregnancy and lactation. This is a serious state of affairs because the consensual decision-making process between patient and professional may be compromised, which, in turn, may give rise to medical-legal issues.