Purpose: Dyslexia is a common learning disorder that affects reading and writing abilities and could have a significant impact on family functioning and child development. Despite the availability of educational interventions, many families of children with dyslexia continue to experience difficulties in handling negative emotions and parent–child dyadic interactions associated with the specific disabilities. The present study examines the effectiveness of multiple family narrative therapy (MFNT), a novel family-based intervention that combines narrative therapy and multiple family approaches, in addressing invisible impacts of dyslexia on parents and children at intrapersonal and interpersonal levels. Method: A multi-site randomized controlled trial was undertaken with 54 Hong Kong Chinese families of children with dyslexia. Results: Results revealed that parents experienced a significant reduction in psychological distress, while no significant improvement in their ratings of parent–child relationship. Conversely, children reported no significant reduction in their psychological distress but a significant drop in their ratings of parental overprotection and indifference. Conclusion: These findings suggest that MFNT might have differential effects on parents and children at intrapersonal and interpersonal level, and these effects sustained at 3-month follow-up. Future studies with larger samples and longer follow-up periods are warranted to confirm the sustainability of intervention effects in both children and parents.