We describe or redescribe five species of mites in the genus Ljunghia Oudemans (Acari: Laelapidae), all associated with trapdoor spiders (Liphistiidae) in Southeast Asia. Ljunghia bristowi (Finnegan) is associated with several species of Liphistius in Malaysia; Ljunghia annamitica sp. nov. occurs with two species of Qiongthela in Vietnam; and Ljunghia uttaradita sp. nov., Ljunghia lannaensis sp. nov., and Ljunghia schwendingeri sp. nov. are associated with unidentified species of Liphistius in Thailand. We provide a world key to females of the genus Ljunghia and review the systematics and biology of the genus.