The defect structure of a crystal of the urea inclusion compound (UIC) of 2,10-undecanedione was investigated using Synchrotron White Beam X-ray Topography. X-ray transmission topographs recorded from different regions show that the crystal is divided into several twin domains. Each region in the crystal is revealed on the topographs by orientation contrast arising from the mutual misorientation of adjacent regions. Using a combination of pinhole Lane pattern analysis and topographic orientation contrast analysis, the twin operation was determined to be consistent with an approximately 60 degrees rotation about the orthorhombic c-axis. Possible twin boundary structures are also presented. Other defects such as dislocations and inclusions are also characterized.