Background: Bell's palsy (BP) is a common cranial neuropathy causing acute unilateral lower motor neuron facial paralysis and idiopathic, unilateral or bilateral paralysis of the facial nerve without any associated disorders. Aim: To evaluate the effect of health educational guidelines on knowledge and practices of mothers having children with Bell's Palsy. Design: A quasi-experimental research design was used. Setting: This study was conducted at physical therapy department of Beni-Suef Hospital. Subject: 100 mothers and their children were selected randomly. Tools: Two tools were used for data collection, Tool₁: A Self-administered questionnaire: Developed by the researchers and used to assess characteristics of mothers and their children also mothers' knowledge about Bell's palsy (pre, post, and at follow up) phases of guidelines implementation. Tool₂: An observational checklist (pre/post and follow up tests) to evaluate mothers' practices in relation to their children with Bell's palsy such as pain relieving, eye care, follow up with doctor,  mouth and dental hygiene, maintaining muscle tone and facial palsy yoga exercise. Results: There were highly statistically significant differences (P<.0001) regarding mothers knowledge and practices before, immediately after and at follow up phases of guidelines implementation. Conclusion: The present study concluded that, the educational guidelines had a positive effect on mothers' knowledge and their practices about their children with Bell's palsy. Recommendations: Continuous ongoing in-service educational programs to nurses, mothers and caregivers are necessary to improve their knowledge, increase their awareness, follow-up and care of their children to decrease health complications.