Background: It was aimed to investigate the relationship between sleep duration and chronic diseases and geriatric syndromes in geriatric patients. Materials and Methods: Our cross-sectional study included 174 patients admitted to the geriatric outpatient clinic for the first time between January 2024 and June 2024. Patients under 65 years of age, with active infection, terminal illness, diagnosis of malignancy, and history of trauma and infection in the last month were excluded from the study. In our study, in accordance with the recommendations of the ‘National Sleep Foundation’ and the ‘American Academy of Sleep Medi-cine (AASM)’, we considered sleep duration over 8 hours/day as long sleep in geriatric patients. Results: In our study, 107 geriatric patients with no long sleep duration (≤8 hours) and 67 geriatric patients with long sleep duration (˃8 hours) were included. There was no significant difference between the two groups in terms of age and gender (p=0.174, p=0.739). There was no significant difference between the two groups in terms of chronic diseases, number of chronic diseases and number of medications. Sarcopenia (%49 vs %33, p=0.046) and malnutrition (%35 vs %21, p=0.041) were found to be significantly higher in patients with longer sleep duration. There was no statistically significant difference between the two groups in terms of frailty, depression, cogni-tive status, basic and instrumental activities of daily living (p=0.208, p=0.062, p=0.097, p=0.110, p=0.117). Conclusions: Sarcopenia and malnutrition were observed at a higher rate in patients with long sleep duration. Based on this, sarcopenia and malnutrition screening should be emphasised in geriatric patients with long sleep duration.