The clinical features of Lophomonas blattarum infection in 26 patients with bacterial pneumonia were analyzed. Common manifestation included fever, cough and breathlessness. Computed tomography (CT) showed interstitial change and alveolar exudation. The parasites were found in sputum smear and from the bronchoalveolar lavage fluid (BALF). Metronidazole was effectively used to cure the pulmonary infection of L. blattarum.