Background: Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity and impulsivity which may result in mothers’ distress, low sense of family coherence and impairment in well-being which all in turn influence family functioning. Aim: This study aimed to examine the relationship between family functioning and sense of coherence, psychological distress, and well-being among mothers of children with attention deficit hyperactivity disorder. Design: A descriptive correlational design was used in carrying out this study. Setting: This study was conducted at pediatric outpatient clinics in El Azazi Hospital for mental health, Alsharkia Governorate. Subjects: A purposeful sample of 60 mothers of children with ADHD were recruited for this study. Tools: Six tools were used in this study: Socio demographic data sheet, The Hopkins Symptom Checklist–10 (HSCL-10), WHO (five) Well-being Index, The Strengths and Difficulties Questionnaire (SDQ; parent version), Sense of Coherence (SOC) Scale and Family Assessment Device - General Functioning Scale. Results: General family functioning was negatively statistically significantly correlated with father education, mother education, and family income. Psychological distress among mothers of children with ADHD was positively statistically significantly correlated with general family functioning and child behaviors (SDQ), while it was negatively statistically significantly correlated with psychological wellbeing and family sense of coherence. General family functioning was positively statistically significantly correlated with child behavior (SDQ), while it was negatively statistically significantly correlated with family sense of coherence. Conclusion: Behaviors of children with ADHD affected their mothers, which disturbed their psychological wellbeing and led to psychological distress. Increasing psychological distress in mothers of children with ADHD made disturbances in their sense of family coherence and more problematic general family functioning. The main influences of general family functioning were family sense of coherence and family income. Recommendation: Training program for mothers with children with ADHD is recommended with emphasis on effective parenting strategies and enhancing self-esteem and locus of control can help them in parenting their children and improving their family functioning.