A new species of Capparis L., C. lianosa Fici & Souvannakhoummane, is described and illustrated from limestones of the Muang Ngoi District, Luang Prabang Province, in northern Lao PDR. The new species, belonging to Capparis sect. Monostichocalyx Radlk., is related to C. zeylanica L., differing in several characters as the shorter stipular thorns, the leaves with apex acuminate, the shorter, glabrous or glabrescent gynophore and the flattened stigma.