Study aim: The aim of this study was to develop a Minimum Data Set for Incontinence-Associated Dermatitis (MDS-IAD), to psychometrically evaluate and pilot test the instrument in nursing homes. Comparable to the MDS for pressure ulcers, the MDS-IAD aims to collect epidemiological data and evaluate the quality of care. Materials and methods: After designing and content/face validation by experts and clinicians, staff nurses assessed 108 residents (75.9% female, 77.8% double incontinent) in a convenience sample of five wards. A second nurse independently assessed fifteen residents to calculate inter-rater agreement (p(0)) and reliability [Cohen's Kappa (kappa)]. Results: The kappa-value for 'urinary incontinence' was 0.68 [95% confidence interval (CI) 0.37-0.99] and 0.55 (95% CI 0.27-0.82) for 'faecal incontinence'. The P-0 for severity categorisation according to the Ghent Global IAD Categorisation Tool (GLOBIAD) was 0.60. IAD was diagnosed in 21.3% of the residents. IAD management mainly involved the application of a leave-on product (66.7%), no-rinse foams (49.1%), toilet paper (47.9%), and water and soap (38.8%). Fully adequate prevention or treatment was provided to respectively 3.6% and 8.7% of the residents. Conclusion: This instrument provides valuable insights in IAD prevalence at organisational level, will allow benchmarking between organisations, and will support policy makers. Future testing in other healthcare settings is recommended.