Multiple operations applied on a big RadBitmap can cause OutOfMemoryException because of used and not disposed unmanaged resources in a WriteableBitmap object. Steps to reproduce: - Execute multiple times the Rotate tool Observe: The memory goes up and retains such. Expected: The unmanaged memory is cleared. Findings: the memory leak is related to the WPF class WriteableBitmap which is internally used by the RadBitmap. Attached is a sample project illustrating the problem using only WPF classes. Note: At this point, we are not aware of a possible fix.