Abstract Background: Asthma in childhood is strongly associated with allergy, especially in developed countries. Common exposures such as tobacco smoke, air pollution, and respiratory infections may trigger symptoms and contribute to the morbidity and occasional mortality. Asthma is a highly prevalent chronic respiratory disease affecting 300 million people world-wide. Aim of the work: The aim of this study is to assess prevalence of bronchial asthma among primary school children and identify associated symptoms and its risk factors. Patients and methods: The present study was conducted in among 1170 children in primary schools in Assiut City in Upper Egypt. All children had inclusion criteria of age between 6-12 of primary school children. Data were collected by two questionnaires. Screening was done at two (2) steps. First step screening: children were screened for chest symptoms. The questionnaire was given to 1300 pupils, the number of pupils who respond to us were 1170 and those pupils become the screened number for our study, the age of those children range between 6-12 years old and the number of girls were 40.5% and the number of boys were 59.5%. Second step screening: All children who selected from first step screening who reported specified respiratory and asthmatic symptoms were selected and assessed individually for the second step questionnaire, as the numbers of those children were 84 children. For every diagnosed asthmatic child, we selected randomly a normal child from the pupils list inside each class. The questionnaire filled by the researcher inside the classes to have total number of 168 pupils. Results: Among asthmatic students males constituted 53.6% and females 46.4%. The prevalence of asthma among the studied students was 7.2%. Asthma was not significantly associated with age and gender. The prominent symptoms of asthma were wheeze 100%, cough 96.4% and dyspnea 40.5%. In our study 70.2% of children with asthma begun wheezing before 2 years age. The severity of asthma among studied children was mild asthma in 52.4%, moderate asthma in 40.5% and severe form of asthma in 7.1% as the frequency of attacks in past year was 1-2 times / year 33.3%, 3 times / year 40.5% and more than 4 times / year in 26.2%. The impact of symptoms on health among studied school children 100% of nocturnal awaking, 96.4% of emergency room visits and 66.7% of hospital admission. There was non-significant difference between asthmatic and non-asthmatic group regard to low weight for age (<5th percentile) and height for age. There was significant difference between asthmatic and non-asthmatic group regard to normal weight for age (5th –95th percentile) and overweight for age (>95th percentile). This study revealed that the presence of one type or more of other allergic disease (skin 23.8%, nasal 66.7% and eye 16.7%) was significantly associated with asthma (p = 0.000). History of asthma and other allergic conditions in the family was significantly associated with asthma in the studied children (p = 0.000). Using logistic regression analysis: a positive family history of allergy and the presence of other one or more allergic diseases were significantly associated risk factors for asthma. The triggering factors incriminated most for the attacks were dust (96.4%), smoke (92.9%), odors (80.9%) cold air (86.9%) drugs (9.5%), temperature changes (59.5%). Upper respiratory tract infections were the precipitating factor in more than two thirds of the studied children (92.9%). Exercise as a triggering factor of asthma occurred in 46.4% of the studied children in this study and has been reported in about 11.9% of the general healthy children. There was significant association between asthma and presence of family pets in the home as birds (83.3%), dogs (7.1%) and cats (13.1%). In this study there was significant association between asthma and family size. Keywords Bronchial asthma prevalence, Risk factors