Mutant mouse lines are important tools to elucidate gene function as observed phenotypes can mostly be attributed to a known genotype. The German Mouse Clinic (GMC, http://www.mouseclinic.de) as an open-access platform offers standardized and comprehensive phenotype analysis of mutant mouse lines and screens for potential new mouse models of human diseases. In the GMC, mouse cohorts pass through 14 different screening modules in a strictly defined workflow in the course of primary screen where up to 240 physiological parameters per mouse are measured. Screening many mouse cohorts in multi-parallel workflows is a logistical challenge and requires appropriate IT support and well-defined data infrastructure. Therefore, we developed a web-based database application – MausDB – for the GMC that serves as a central data platform accessible by all GMC users. MausDB supports scheduling of mouse lines to the phenotyping pipelines by work list management functions. Phenotyping data upload to MausDB and re-export is done via spreadsheet files. MausDB also offers standard mouse management functions (breeding support, cage management, etc.) and integrates phenotype data with line/genotype data and other metadata on the individual mouse level. For the GMC, this is a prerequisite for inter-line data analysis, data mining and data exchange in a cross-European phenotyping effort (EUMODIC). Although primarily developed for the GMC, MausDB also proved to be useful for other mouse facilities due to its general purpose design and intuitive user interface. Hence, we offer MausDB to the mouse community as open source software under the terms of the GNU General Public License.