OBJECTIVES: There are several factors that affect the risk of developing dementia. Various studies have shown that defined diagnoses and medications increase or decrease dementia risk. But the relatively small numbers of dementia patients in some of these studies make the interpretation of their results difficult. The aim of this work was to estimate risk factors for dementia in German primary care patients. METHODS: The case-control study included 11,956 primary care patients in the age group 70-90 years with first dementia diagnosis during the index period (01/2010-12/2014) (Disease Analyser, Germany). Furthermore, 11,956 controls without any dementia diagnosis were included after individual matching (1:1) to dementia cases on age, sex, type of health insurance and physician. The practice visit records were used to determine 10-year prior index continuous follow-up. Multivariate logistic regression models were fitted with dementia as dependent variable and the potential predictors. RESULTS: Mean age of patients and controls was 80.4 (SD: 5.3) years. 39.0% of them were male and 1.9% had a private health insurance. In multivariate regression model, the following variables were significantly related to an increased risk for dementia: diabetes (OR: 1.17; 95% CI: 1.10-1.24), lipid metabolism (OR: 1.07; 1.00-1.14), stroke incl. TIA (OR: 1.68; 1.57-1.80), Parkinson disease (OR: 1.89; 1.64-2.19), intracranial injury (OR: 1.30; 1.00-1.70), coronary heart disease (OR: 1.06; 1.00-1.13), mild cognitive impairment (OR: 2.12; 1.82-2.48), mental and behavioural disorders due to use of alcohol (OR: 1.96; 1.50-2.57). Use of statin (OR: 0.94; 0.90-0.99) and proton-pump inhibitors (PPI) (OR: 0.93; 0.90-0.97) were protective for the incidence of dementia. CONCLUSIONS: Risk factors for dementia found in this study were in line with the literature. There is also evidence for a protective effect of statin use with respect to the incidence dementia.  Further studies are required to investigate the association between PPIs and a decreased risk of dementia.