Menispermaceae, a dioecious, largely pantropical family of vines and lianas, consists of approximately 70 genera. In this paper, we present phylogenies (derived using maximum parsimony, maximum likelihood, and Bayesian inference) based on chloroplast atpB and rbcL sequence data for 42 Menispermaceae genera (60 species) and 15 outgroup genera representing all families in the Ranunculales. Results of this work confirm that a clade consisting of Berberidaceae and Ranunculaceae is sister to the Menispermaceae and that Menispermaceae is highly supported as monophyletic. Within Menispermaceae, Menispermum and Sinomenium, two genera with distributions in the Northern Hemisphere, are weakly to moderately supported as sister to all remaining Menispermaceae. Many of the tribes as described by previous workers are not monophyletic. To expand both the data and sampling, we combined our atpB and rbcL data with previously published ndhF data for two additional analyses: 1) for matching species and 2) for all genera available, including those with either atpB/rbcL or ndhF missing (22% missing data). All trees produced from our three analyses were highly congruent, especially where branch support was high. Four major clades were recovered from all analyses and are informally named. Superimposing our geographical distributions on our atpB/rbcL phylogeny indicates that many well supported clades have distributions on multiple continents, probably due to both vicariance and dispersal. Several previous hypotheses regarding trends in character evolution are tested; our phylogenies suggest that the following are all derived character states within the family: arborescent habit; acrodromous, peltate, compound, or lobed leaves; absence of condyle and endosperm; smooth endosperm; fused stamens; and tricolpate pollen.