Background: At our institution, patients of all ages with extremely severe motor and intellectual disabilities (ESMID) receive comprehensive management similar to intensive care for "extremely ill patients." Some patients with ESMID develop frequent infections that are difficult to manage. The purpose of this study was to identify risk factors for frequent infections in these patients.Methods: Thirty-seven patients with ESMID who were treated for infections at our institution between September 2018 and August 2019 were retrospectively investigated. Frequent infection was defined as three or more episodes of infection and antimicrobial treatment in one year. Infection status and potential risk factors for frequent infections (patient background factors, severity score, hematological parameters, anthropometry index, and parenteral nutritional status) were examined in univariate and multivariate analyses.Results: Frequent infections occurred in 11 of the 37 patients (29.7%) during the study period, including respiratory and urinary tract infections. Univariate and multivariate analyses suggested hypoalbuminemia (p<0.01) and hypertriglyceridemia (p<0.01) were independent risk factors for frequent infections.Conclusions: Hypoalbuminemia and hypertriglyceridemia may be risk factors for frequent infections in patients with ESMID.