In dementia of the Alzheimer’s type, memory and language impairments coexist, occur early and aggravate with time. The aim of this study was to assess the effect of our proprietary language function stimulating programme on cognitive functions and the maintenance of language skills in patients with mild-to-moderate Alzheimer-type dementia as well as to evaluate the programme’s effectiveness depending on patients’ age, sex, education, severity of dementia and level of motivation. The intervention group (54 patients) and the control group (34 patients) were divided into subgroups according to the severity of dementia (mild/moderate). Tests such as the Mini-Mental State Examination, the Clock-Drawing Test, the Boston Naming Test and picture description were performed at 1, 3, 6, 9 and 12 months. In the course of 1 year, the Mini-Mental State Examination scores in the intervention group improved on average by 0.87 points, whilst in the control group they declined by 1.32 points over the same period of time. Statistically significant differences in the Clock-Drawing Test were found at 6 and 12 months, with the mean score differing by 0.98 and 1.35 points respectively across the groups. The score difference in the Boston Naming Test grew gradually. At 3 months it was 3.67 points, amounting to as much as 7.96 points at 12 months. For the picture description task, the mean scores at 12 months increased by 1.18 points in the intervention group in the mild dementia subgroup and by 0.66 points in the moderate dementia subgroup. In the control group, the scores decreased. The use of our proprietary training programme, specially designed to stimulate language functions in patients with mild-to-moderate Alzheimer-type dementia, facilitates the maintenance of general cognitive function and improvement of language skills, and its effectiveness increases with the patient’s motivation. This confirms the importance of supplementing non-pharmacological interventions used in Alzheimer-type dementia with language therapy programmes.