Honeybees, Apis mellifera L. are the most economically valuable pollinators of agricultural crops worldwide. This study was to estimate extent and possible causes of honeybee colony losses in Upper Egypt (Qena & Luxor Governorates) during the fall and winter of 2009/2010 and 2010/2011. The survey of colony losses and potential causes was via questionnaire method. Data of 318 questionnaires completed by beekeepers were analyzed. The collected data indicate that, the number of managed honeybee colonies dropped an estimated 15.15% in the 2009/2010 fall and winter and 30.73% in the 2010/2011 fall and winter with average losses 23.28% during the two years. Survey information indicates that, colony losses range widely depending on operation size. Commercial beekeepers (those operating more than 150 colonies) experienced lower total losses as compared to hobbyist; intermediate and semi-commercial beekeepers. Oriental hornet (Vespa orientalis); weather; American foulbrood (AFB) and poor quality queens were the leading self identified reasons of losses in their operations as reported by most beekeepers.