We have used high-resolution triple axis X-ray diffraction analyses to monitor the effects of radiation damage by Cu Ka X-rays on the defect structure in hen egg white lysozyme crystals. At long irradiation times (greater than 45 h of X-ray exposure) we observed the expected decrease in peak intensity and increase in the angular extent of the peak breadth. In contrast, the initial stages of irradiation showed relatively complex changes in both the peak breadth and the intensity: during the period from 25 to 45 h of irradiation the angular breadth of the intensity (both the full width at half maximum and the full width at 1% of the maximum intensity) decreased to a minimum value. Some possible reasons for this complex behavior are discussed.