Neurodegenerative diseases (NDDs) pose significant challenges to couple relationships. Existing research has predominantly focused on the impact of Alzheimer’s disease (AD) on various types of dyads, resulting in significant advances in the field. However, despite a keen interest in transdiagnostic approaches , a comprehensive review addressing dyadic processes underlying the functioning of couple relationships across different NDDs is lacking. This meta-synthesis aimed to fill this gap by identifying, analysing, and integrating findings from qualitative studies examining couples facing different NDDs. Searches were conducted in four databases, identifying 35 articles meeting several inclusion criteria. A thematic synthesis was performed, identifying three interdependent themes : ‘Disease-related challenges’, ‘Dyadic interactions’, and ‘Dyadic identity’. They emphasise that stress, social changes, the perception of time, and uncertainty are major challenges for partners.They also show how dyadic interactions such as communication are transformed and how partners strive to maintain their shared identity despite the progressive loss of the relationship’s core components. This synthesis highlights key implications for clinical practice and future research, including the need to integrate disease- specific characteristics to interventions and understand the couple’s functioning patterns and their evolution throughout the disease.