The present study was undertaken to investigate whether patients with a history of peptic ulcer disease (PUD) have serological features indicative of the presence of more severe gastritis, compared to patients without a history of PUD. In addition we investigated whether current chronic use of non steroidal anti-inflammatory drugs (NSAIDs) was associated with serological features indicative of a chemical (type C) gastritis. In total 850 consecutive outclinic patients were interviewed by a standard questionnaire with emphasis on demographic data, diagnosis, chronic use of NSAID, and history of PUD. Serum pepsinogen A (PgA) and pepsinogen C (PgC), the PgA:PgC ratio, and IgA and IgG antibodies to H. pylori were measured in all patients. After controlling for age, sex, H. pylori seropositivity, and presence of RA, a correlation was found between a decreased pepsinogen A:C ratio and the use of NSAID. Patients with a history of PUD have serological features indicative of a persistently more severe gastritis. Secondly we found serological evidence for the existence of a chemical (type C) gastritis in NSAID users.