Abstract Aim I sotrema is a monophyletic subgenus of A ristolochia with species in E ast A sia and N orth/ C entral A merica. Earlier studies, based on limited sampling, suggested that the A sian and A merican species do not form two reciprocal sister clades. We reconstructed phylogenetic relationships within I sotrema to infer the biogeographical events that have shaped its present‐day distribution. Location E astern A sia, N orth A merica, M exico, C entral A merica. Methods We performed parsimony and Bayesian phylogenetic analyses of 54 accessions using three chloroplast regions. The temporal origins were traced with relaxed phylogenetics and penalized likelihood using fossil calibrations; these methods were combined with ancestral area reconstructions in a comparative approach using statistical dispersal–vicariance analysis ( S‐DIVA ) and dispersal–extinction–cladogenesis ( DEC ) analyses. Results The ancestors of the herbaceous eastern N orth A merican species and the woody species probably diverged during the O ligocene. The woody species form a Neotropical and a N orth A merican/ E astern A sian clade. Diversification in the Neotropical and N orth A merican/ E astern A sian clades occurred mostly in the M iocene. In the latter clade, two further intercontinental splits are reconstructed: between the exclusively western N orth A merican A ristolochia californica and most of the A sian taxa, and between A . manshuriensis and A . tomentosa . Main conclusions The present distribution of I sotrema developed via a number of dispersal, vicariance and extinction events. The disjunct distributions observed may be the result mainly of non‐synchronous events (e.g. a decrease of mean annual temperature in the O ligocene and the development of unfavourable conditions across the B ering land bridge) that were responsible for the fragmentation of the mesophytic forests. Later diversifications may be correlated with events such as the orogeny of the W estern C ordillera and A ppalachian M ountains, the development of extensive grasslands in N orth A merica, and the mainland extension of C entral A merica southwards to western and central P anama.