To evaluate verbal communication ability in the elderly, we developed a new portable "mini-communication test (MCT)" with 13 sub-scales, which was constructively validated based on 45 items from other reported scales. Clinical reliability and validity were tested in 354 inpatients in a long-term care hospital (81.9 +/- 8.3 years old) and 124 inpatients (80.39 +/- 8.1 years old) and 34 outpatients (76.5 +/- 7.0 years old) in Kyorin University Hospital. All patients were evaluated in approximately 7 minutes each. The test-retest correlation coefficient was 0.99. Inter-rater coefficient of variation was 0.107. The Cronbach alpha value of the test was 0.93. MCT positively correlated with the Barthel Index (r = 0.65, p < 0.01). Hasegawa Dementia Scale Revised version (r = 0.93, p < 0.001) and Vitality Index (r = 0.66, p < 0.01). MCT could be a new tool to assess communication ability in elderly patients with or without dementia.