Economic losses due to suni-bug (Eurygaster spp. and Aelia spp.) damage are important for the cereal industry in East European and Middle East countries. Samples of five durum wheat cultivars (Diyarbakir, Firat, Ege, Svevo, and Zenith) with zero, medium, and high levels of suni-bug damage were used to determine the effects of suni-bug damage on milling properties and semolina quality. As the damage level increased, semolina yields of all cultivars decreased significantly. The loss of semolina yield was greater than decreases in total yield of semolina plus flour, indicating that semolina yields were affected to a higher extent than were flour yields. The ash contents of the semolina samples increased significantly in all cultivars with increasing suni-bug damage. The falling number values were not correlated with suni-bug damage level and amylase activities of all samples were quite low. The pasting properties did not differ to a great extent depending on the suni-bug damage level. Gluten quality of semolina samples substantially deteriorated as suni-bug damage level increased, as determined by SDS-sedimentation and mixograph analyses. It was concluded that suni-bug damage would decrease profits of durum wheat millers substantially by affecting semolina yield and quality.