Off-label use of anticholinergic agents (atropine eye drops) administered sublingually are a first-line treatment in standard clinical practice in France to treat sialorrhea in patients with neurological conditions. The ability and willingness to using and administering such medication have become key factors to ensure safe and effective therapy. Given that the critical aspects for ophthalmic product development differ from those for oral medicine, the objectives of this study were to investigate patient acceptability of atropine eye drops for treating sialorrhea. A multi-centric, cross-sectional study using the CAST-ClinSearch Acceptability Score Test methodology was conducted in France between February 2021 and April 2023. In total, 31 evaluations were collected. Most patients were males (74.2%) and the mean age was 51.6 ± 20 years. Poor acceptability was reported in real-life settings. A lack of a suitable administration device combined with excessive saliva flow and patient disabilities made it difficult to ensure the required dose intake. Due to the bitter taste of the drug, poor palatability of the product appeared to be a key concern for oral administration. Designing a suitable form of atropine in accordance with the specificities of patients with neurological disabilities is needed to ensure the effective treatment of sialorrhea.