Objectives The association between anticholinergic load-based Anticholinergic Risk Scale scores and nutritional status is unclear in Japanese patients. The aim of this study was to establish whether anticholinergic load affects the nutritional status of geriatric patients in convalescent stages. Design Retrospective longitudinal cohort study. Setting Convalescent rehabilitation wards. Participants Of the 1490 patients aged ≥65 years who were discharged from convalescent rehabilitation wards between July 2010 and October 2018, 908 patients met the eligibility criteria. They were categorized according to the presence or absence of increased anticholinergic load from admission to discharge. Measurements Demographic data, laboratory data, the Functional Independence Measure were analyzed between the groups. The primary outcome was Geriatric Nutritional Risk Index (GNRI) at discharge. Multiple linear regression analysis was performed to analyze the relationship between anticholinergic load and GNRI at discharge. Results Multiple linear regression analysis after adjusting for confounding factors revealed that anticholinergic load was independently and negatively correlated with GNRI at discharge. Particularly, the use of chlorpromazine, hydroxyzine, haloperidol, metoclopramide, risperidone, etc. increased significantly from admission to discharge. Conclusion Increased anticholinergic load during hospitalization may be a predictor of nutritional status in geriatric patients.