In this article the authors describe a case of atypical stenosis of the lachrymal excretory system in Rubinstein-Taybi syndrome (RTS) characterised by morphologic anomalies of the lachrymal bag and by alterations of the osseous structure of the nose. A 9-year-old girl, with typical findings of RTS, was affected by recurrent acute dacryocystitis and tearing. Ocular examination revealed bilateral reflux with mucous and purulent material flowing back after digital pressing: low and bilateral nose-lachrymal duct obstruction was the main cause of the reflux as confirmed by orifice probing, lachrymal drainage system irrigation and spiral CT examination using hydrosoluble contrast medium. The multiplanar reconstruction obtained from CT scanning shows that the right lachrymal sac has an abnormal shape (‘grape-bunch’ image) and that the left one has various bulgings, or swellings, in its shape. The ‘grape-bunch’ lachrymal bags are the most unusual features of our patient’s lachrymal system and it is important to consider the difficulties that could occur during surgery because of the abnormal bag shape and because of the increased bone thickness in RTS patients. The ‘grape-bunch’ lachrymal sac is a truly unusual anatomical feature and, most probably, it could be distinctive of this syndrome.