An association between filamentous organisms and gastric carcinoma has been reported in gastric biopsies. Review of 45 Papanicolaou-stained gastric brushing specimens revealed filamentous organisms in two cases. In both cases, gastric carcinoma was confirmed on follow-up. Cytopathologists should be aware that the identification of filamentous organisms in gastric brushings is a specific, although insensitive marker of gastric cancer.