AIMS: We examine the dementia assessment with focus on age and gender differences. METHODS: Data from the national quality database, Swedish Dementia Registry (SveDem), including 6,937 dementia patients diagnosed during 2007-2009 at memory clinics were used. We have studied the use of investigations for dementia diagnostics such as cognitive tests, blood and cerebrospinal fluid analyses, electroencephalography, radiological examinations and assessments of functions. Severity of cognitive impairment was assessed with the Mini Mental State Examination (MMSE). RESULTS: There was a significant decrease in the number of total tests used in the elderly group (>75 years) when compared with the middle-aged group (65-75 years) and younger patients (<65 years). The oldest group was examined with 4 of 11 possible tests, the middle-aged group had 5/11 tests performed and the youngest age group 6/11 tests. There was also a significant gender difference in the diagnostic workup, however, mostly attributable to age. The number of tests positively correlated with the level of cognition assessed by the MMSE. CONCLUSION: We show here for the first time the impact of age, gender and MMSE score on the dementia diagnostic workup in a large memory clinic patient population in one country.