Background: Children with intellectual disability are at an increased risk of bronchial asthma. Unfortunately, no specific guidelines exist for dealing with and managing Intellectually Disabled (ID) children with Bronchial Asthma (BA). Recent innovations in medical care have shifted asthma treatment from hospitalization to ambulatory care. Consequently, mothers' care has become the most important part of the treatment, and almost all treatment responsibilities have fallen on them. Aim: to determine asthma-related knowledge, management, and burden among mothers of intellectually disabled children with bronchial asthma. Design: An explanatory sequential mixed design was used. Settings: All governmental intellectual disability schools distributed in 6 educational directorates affiliated with El-Beheira Governorate (6 mixed gender schools). Subjects: Purposive sample of mothers with children with intellectual disability and bronchial asthma. Tools: Four data collection tools were used to collect qualitative and quantitative data for the study; For quantitative data, three structured interview schedule tools were used as follows: Tool I: Personal Characteristics and Health Profile of Children, Tool II and III: Asthma-Related Knowledge and Management of Mothers Regarding their Intellectually Disabled Children with Bronchial Asthma. While for qualitative data, Tool IV Focus Group Discussion Guide (FGD) for the mothers of Intellectually Disabled Children with Bronchial Asthma was used. Results: It was found that the majority (78.6%) of mothers with a good BA knowledge level had a good BA management score. On the other hand, the majority (97.7%) of mothers with poor BA knowledge had a poor BA management score (X2: 51.3, p <0.001). Regarding the qualitative data, it was clustered into four categorical schemes: 1: Caring role, 2: Constant concern, 3: Caring impacts on life and 4: Unmet needs. Conclusion: it can be concluded that more than half of the mothers of intellectually disabled children with bronchial asthma had a poor knowledge score. Moreover, more than two-thirds of them had a poor management score. Caring for intellectually disabled children with bronchial asthma negatively affects mothers' health, relationships, social status, financial stability, emotional and psychological well-being. The mothers struggle with unmet social, psychological, and financial needs. Recommendations: The current study recommended raising awareness, designing an asthma management training program and providing psychological and social support for mothers of intellectually disabled children with bronchial asthma to improve the care provided to their children.