This survey aims to provide an updated species checklist of aquatic and semi-aquatic bugs in the intra-Philippine biogeographic Region of Mindoro. An assessment survey of water bugs (Hemiptera, Heteroptera) was conducted mostly by manual collection in selected areas of Oriental Mindoro from 2017 to 2018, in which some of the collecting activities were undertaken by graduate students of Ateneo de Manila University.Twenty-nine aquatic and semi-aquatic heteropteran species were documented and some are known island-endemic species or subspecies, includingEnithares martini mindoroensisNieser & Zettel, 1999,Hydrotrephes stereoides mindoroensisZettel, 2003,Aphelocheirus freitagiZettel & Pangantihon, 2010,Rhagovelia mindoroensisZettel, 1994,Rhagovelia raddaiZettel, 1994,Rhagovelia potamophilaZettel, 1996 andStrongylovelia mindoroensisLansbury & Zettel, 1997, which were found in new areas in the Region. In addition, there are also new records for the Island that have already been documented in other parts of the Philippines, such as the Philippine-endemicOchterus magnusGapud & San Valentin, 1977 andHebrus philippinusZettel, 2006 and the widely-distributed backswimmersAnisops nigrolineatusLundblad, 1933 andAnisops rhomboidesNieser & Chen, 1999. Several undescribed specimens and potentially new species are also discussed in this paper. Further surveys in the other parts of Mindoro and in the other regions of the Philippines, are encouraged to produce a comprehensive baseline data of heteropteran species richness in the country.