To study the distribution and diversity of Bartonella in rodents from Thailand, 330 rodents belonging to 13 species were tested. The majority (80.6%) of rodents examined belonged to the genus Rattus. Bartonellae were cultured from 41.5% of the rodents with a wide range of prevalence by host species and regions. Sequencing of gltA revealed diverse Bartonella strains. Bartonellae from Rattus spp. belonged to 23 variants and clustered with Bartonella coopersplainensis, Bartonella elizabethae, Bartonella phoceensis, Bartonella rattimassiliensis, Bartonella tribocorum, and an unknown geno-group. Bartonellae from Bandicota spp. belonged to six variants and clustered with B. coopersplainensis, B. rattimassilliensis, and B. tribocorum. Three variants from Mus spp. clustered with B. coopersplainensis or B. rattimassilliensis. The only isolate from a Berylmys berdmorei fell into the B. tribocorum group. The observations highlight the need to study these agents for their role in human febrile illnesses of unknown etiology in Thailand and elsewhere in Asia.