Natural History Museum Rijeka is a regional museum that collects, preserves and documents the objects of natural science primarily from the Primorsko-Goranska County (Croatia). More than 90,000 collected specimens are present in 28 museum collections. The aim of this Project was to create a searchable online museum database so our colleagues and virtual visitors can freely browse and access the basic information about many specimens from Natural History Museum Rijeka inventory register. Each database record includes information and an image of the selected museum object. Particularly interesting, rare and protected species have additional detailed description and photo. There are approx. 13,000 museum object records from those collections available online, and the data presented on the portal changes constantly as the result of ongoing curatorial research. Using FileMaker relational databases, we developed our own custom-made Museum collection management system. This system is a backbone of our Collections Online Project. Work on the Project, to put our collections online is constantly ongoing and includes digitizing museum objects and adding new ways to access and present them more easily.