Lophomonas blattarum is a flagellate protozoan parasite which was originally described as a commensal in the gut of cockroaches. From the 1990s, reports started coming out of peoples Republic of China about its possible role in bronchopulmonary infections, and this was followed by reports from some other parts of the world as well. There had been some skepticism regarding the misidentification of bronchial ciliated epithelial cells as L. blattarum, but recent use of molecular diagnosis has come as an aid in clearing the controversy. This review focuses on the various aspects of the parasite including its biology, epidemiology, clinical manifestations, laboratory diagnosis, and the treatment aspects. Molecular diagnosis has recently been employed and more reports concerning its validation is needed. More basic research concerning the genomic and proteomic analysis is necessary to develop reliable molecular and serological tests for this parasite in future.