Aim Elderly patients with autoimmune gastritis might have different symptoms than those of young patients. The aim of the present study was to compare presented symptoms and laboratory parameters associated with autoimmune gastritis in both old and young age groups. Methods A total of 355 patients with autoimmune gastritis were stratified into two groups: 65 years or older (n = 119, mean age 69.47 ± 5.027 years), and under 65 years (n = 236, mean age 45.79 ± 10.51 years). These two groups were then evaluated and compared by means of clinical symptoms, concurrent autoimmune diseases, serum gastrin, vitamin B12 and chromogranin A levels, and the presence of enterochromograffin‐like cell hyperplasia. Results Among 119 older patients, 35 had dyspeptic symptoms, and 84 patients were referred for vitamin B12 and/or iron deficiency. In the younger group (n = 236), there were more patients who had dyspeptic symptoms (36 vs 200, P < 0.001). Serum gastrin (726.68 ± 266.183 vs 214.36 ± 104.62 pg/mL, P < 0.001) and chromogranin A (301.26 ± 172.95 vs 106.59 ± 67.66 ng/mL, P < 0.001) levels were significantly higher, and the presence of enterochromograffin‐like cell hyperplasia was more frequent (113 vs 31, P < 0.001) in older patients than younger patients. Polyautoimmunity (66.3% vs 24.5%) and multiple autoimmune syndrome (17.6% vs 5.5%) were more common in older patients (P < 0.001). Conclusions There are differences in the clinical characteristics and the laboratory parameters between patients with autoimmune gastritis that are older and younger than 65 years‐of‐age. Elderly patients with autoimmune gastritis were investigated more commonly for vitamin B12 and/or iron deficiency. Polyautoimmunity and multiple autoimmune syndrome were more common, and serum gastrin and chromogranin A levels were significantly higher in older patients. Geriatr Gerontol Int 2016; ••: ••–••.