This corpus consists of semi-spontaneous speech data produced by elderly residents of the Basilicata region in Italy. In total, 40 individuals participated: the patient group consists of 20 participants with a diagnosis of dementia (9 cases of Alzheimer’s disease, 2 patients with mixed dementia, 5 patients with not-further-specified dementia, 3 patients with vascular dementia, and 1 patient with frontotemporal dementia), and the control group consists of 20 healthy individuals matched for age, gender, and geographical origin. Three linguistic tasks were administered to all participants: two narrative tasks (the first one was about an excursion or a trip, and the second was about Christmas festivities), and an image description task. This resulted in 8 hours and 50 minutes of recorded semi-spontaneous speech, which was then transcribed, segmented, and annotated using ELAN. This research project was approved by the Bioethics Committee of the Alma Mater Studiorum - University of Bologna (no. 0072032/2022). Due to the Italian privacy policy, raw data of the corpus (i.e., speech recordings, transcriptions, and clinical information of the participants) is not available. Processed data (i.e., tables of acoustic/rhythmic/lexical/syntactic values, with the name of the speakers masked through an alphanumeric acronym to ensure anonymity) are available from the contact person upon reasonable request.