Three species of woodborers from marine mangrove plants at Mida Creek, Tudor Creek and Gazi Bay along the Kenyan coast are identified. The relationship between the borers and the host mangrove plants (Avicennia, Sonneratia, Rhizophora) are described. Observation of infested plants showed that woodborers - Dicyathifer mannii (Wright, 1866), Sphaeroma terebrans (Bate, 1866) and Cirolana sp. occur on submerged parts of roots (prop-roots and pneumatophores), stems and branches. All the observed species appear to have a host preference. Among the two most frequent marine woodborers, S. terebrans occurs only on Avicennia sp. whereas D. mannii occurs mostly on Rhizophora plants, but also on Sonneratia. The marine woodborers deteriorate the vegetation. Therefore, the present study is relevant to the restoration, conservation and management of mamgroves.