This review aims to draw attention to the features that distinguish drug-induced vasculitis and drug-induced lupus-like disease from those of idiopathic autoimmune syndromes, first and foremost primary vasculitides and systemic lupus erythematosus. Drug-induced vasculitis and drug-induced lupus-like disease are seen in patients treated long term with a drug, and close to 100 drugs representing all pharmacologic classes have been assumed capable of inducing such syndromes. The clinical phenotypes vary from single tissue or organ involvement to severe systemic inflammatory disease dominated by vasculitis and sometimes organ failure.The recent discovery of antineutrophil cytoplasm antibodies in a large serological subset of drug-induced vasculitis/drug-induced lupus-like disease caused by long-term antithyroid drug treatment has opened new avenues for differential diagnostics. Antineutrophil cytoplasm antibodies with specificity to more than one lysosomal antigen, combined with presence of antibodies to histones and beta-2 glycoprotein 1 constitute a unique serological profile for drug-induced vasculitis/drug-induced lupus-like disease.Rational use of laboratory marker profiles is likely to aid in distinguishing drug-induced from idiopathic syndromes. Hence, the use of antineutrophil cytoplasm antibodies and other autoantibodies as biomarkers of different phenotypes of drug-induced vasculitis/drug-induced lupus-like disease is the main focus of this review.