The study was conducted in ElFashir locality, North Darfur State, Sudan, to investigate the main causes of poultry mortality under the opened and semi-opened systems of current poultry farms conditions. The data were collected through a systematic questionnaire distributed to 21 farms representing all farms in the locality. A simple random sampling method was used to select farms. Respondents put land transport at 71.4% as the highest cause of death during the first week of life, and diseases (52.4%). Newcastle disease was identified as the most destructive disease in the study area. Malnutrition caused 47.6%, and lack of biosecurity and cannibalism (15.8%) as major causes of mortality in poultry older than a week. Poor management (51.9%) The density of birds over fodders and drinkers exceeds the recommended number (67.8%) of respondents. Graduates from colleges of animal production and veterinary medicine make up the percentage (73.7%), while graduates of other colleges make up 21% of those who perform the production process and supervision. The study concluded that birds in the study area died due to poor transport condition, diseases, malnutrition, mismanagement and lack of biosecurity measurements. Therefore, it is necessary for authorized sectors to induce intensive extension services and training of farmers and workers about the importance of adopting restrict biosecurity measurements in addition to good nutritional and health management of poultry flocks to sustain commercial production of poultry in ElFashir Locality.