Introduction: Mild cognitive impairment does not meet the criteria for the diagnosis of dementia, but reaching this diagnosis raises concern about the future state of a patient due to the possibility of the conversion to Alzheimer’s disease. Although the aetiology of Alzheimer’s disease is neurodegenerative, the impact of vascular diseases is also taken into consideration. The aim of this study was to assess the impact of vascular diseases in patients diagnosed with mild cognitive impairment on the conversion to Alzheimer’s disease. Material and methods: In each of 101 patients with a diagnosis of mild cognitive impairment, a detailed medical history was taken, taking into account: hypertension, ischaemic heart disease, arrhythmias, myocardial infarction, stroke, diabetes as well as thyroid diseases, head injuries, alcohol abuse, smoking, exposure to toxic substances, surgery under general anaesthesia and the family character of dementia. Clinical follow-ups were scheduled after 6, 12 and 24 months. Results: Amongst 101 patients with mild cognitive impairment, 17 (16.8%) converted to Alzheimer’s disease within two years of observation. The analysis of the distribution of independence tests showed that the conversion is significant for two variables: ischaemic heart disease and myocardial infarction.