FDI World Dental Federation, founded as Fédération Dentaire Internationale, has taken the initiative to develop the Oral Health Observatory, a mobile application to conduct oral health surveys worldwide. The aim is to collect reliable standardized international data on oral health and oral health care via a network of dentists. A proof of concept study project was set up in the Netherlands to test the methodology and to validate the approach. Data about caries, gingivitis, oral self-care and oral health related quality of life were analysed and compared to datasets validated in other studies. The Android app embeds three questionnaires addressing oral health history, status and patient behaviour. One questionnaire was completed by the patient and two by the dentist. The proof of concept study involved two phases: in the first phase, five dentists, regular participants in KNMT-surveys, evaluated the usability of the app; after the first phase, the app was adjusted for a second phase. For this phase an extra 15 dentists were recruited from a group of 20 other dentists: five of them declined to participate. Attention was paid to ensuring there was a proportional representation of gender, age and region. In the second phase the five first and 15 new participants collected data on up to a maximum of 38 patients. Data from this 653 patients correspond with results from previously published surveys on the prevalence of caries and gingivitis in the Netherlands. Hence demonstrating an association between caries and gingivitis with oral self-care, problems eating and experiencing oral pain. This proof of concept study shows that the app makes it possible to collect reliable information on oral health in a short period of time. Both dentists and patients evaluated the methodology as user-friendly. Altogether, the results of this proof of concept study are promising.