Abstract Background The disease trajectory of patients with young onset dementia differs from older patients, as do healthcare requirements. To improve specialized care, more insight in young onset dementia is crucial. The aim of PRECODE‐GP is therefore 1) to conduct an (annual) inventory of the diagnostic workup in all memory clinics in the Netherlands, and 2) to set up a prospective nationwide database including newly diagnosed younger patients with dementia. Methods PRECODE‐GP is part of the PRECODE project, a collaboration between four Dutch Alzheimer centers, Knowledgecenter Dementia at Young Age, Nivel and Alzheimer Nederland. Governance is embedded in the Dutch Memory Clinic Network. Memory clinics are asked annually to fill out a survey on their current diagnostic workup. Eligible patients (<70 years; any type of dementia) are identified by local specialists and recruited via an informed consent procedure providing consent for future linkage to other datasets. Demographics, test results and (etiological) diagnosis are collected in an online database. Results PRECODE‐GP was initiated in July 2019 and has been approved in 36 memory clinics, approval procedure is ongoing in additional 10 clinics. Based on the annual survey (filled out by 21 clinics), standard imaging of the brain occurs in almost half of memory clinics and neuropsychological examination in one third. CSF is performed when deemed necessary by the clinician. A median 250(141‐396) new patients visited the memory clinics yearly, of whom 111(74‐180)(48%) were diagnosed with dementia and 12(4‐36)(6%) were <70 years. To date, 201 young onset dementia patients (age 62±8, 51% female, MMSE 22±5) are included in our prospective database, diagnosed with 140(69%) Alzheimer’s dementia (AD), 29(14%) frontotemporal dementia (FTD), 14(7%) dementia with Lewy Bodies (DLB) and 18(9%) other dementia types. Patients with FTD were youngest (61±6 years), subjects with DLB were most often male (79%), in AD MMSE was lowest (21±5). Conclusion We took the first ...