Mark Malamood,1 Aaron Roberts,2 Rahul Kataria,2 Henry P Parkman,2 Ron Schey2 1Department of Internal Medicine, 2Department of Gastroenterology, Temple University Hospital, Philadelphia, PA, USA Introduction: Gastroparesis symptoms can be severe and debilitating. Many patients do not respond to currently available treatments. Mirtazapine has been shown in case reports to reduce symptoms in gastroparesis. Aim: To assess the efficacy and safety of mirtazapine in gastroparetic patients. Methods: Adults with gastroparesis and poorly controlled symptoms were eligible. Participants were prescribed mirtazapine 15 mg PO qhs. Questionnaires containing the gastrointestinal cardinal symptom index (GCSI) and the clinical patient grading assessment scale (CPGAS) were completed by patients’ pretreatment, at 2 weeks, and at 4 weeks. Primary end point was nausea and vomiting response to mirtazapine using the GCSI. Secondary end point was nausea and vomiting severity assessment using the CPGAS. P-values were calculated using the paired two-tailed Student’s t-test. Intention to treat analysis was used. Results: A total of 30 patients aged 19–86 years were enrolled. Of those, 24 patients (80%) completed 4 weeks of therapy. There were statistically significant improvements in nausea, vomiting, retching, and perceived loss of appetite at 2 and 4 weeks (all P-values