Background <p>Liver cirrhosis, particularly in its decompensated stage, is associated with significant complications, including sleep disturbances. The relationship between sleep quality and muscle abnormality in patients with cirrhosis remains elusive. This study aimed to investigate the association between the Pittsburgh Sleep Quality Index (PSQI)-defined sleep disturbances and skeletal muscle abnormalities, including sarcopenia and myosteatosis, in a cohort of patients with decompensated cirrhosis.</p> Methods <p>We conducted a cross-sectional analysis of 505 adult patients with decompensated cirrhosis, excluding those with malignancy, acute-on-chronic liver failure, severe hepatic encephalopathy, or incomplete data. Muscle status was determined by the skeletal muscle index (SMI) and intramuscular adipose tissue content (IMAC) on computed tomography (CT), respectively.</p> Results <p>The median PSQI score was significantly higher in patients with coexistent sarcopenia and myosteatosis compared to those with no or isolated muscle abnormality (<i>P</i> &lt; 0.001). Multivariate analysis revealed that concomitant muscle abnormalities (OR: 3.48, <i>P</i> = 0.029) and body mass index (BMI) (OR: 0.95, <i>P</i> = 0.040) as independent predictors of poor sleep quality. Additionally, in the subgroup with preserved liver function and younger age, the differences in PSQI score across various states of skeletal muscle are more pronounced.</p> Conclusion <p>Skeletal muscle abnormalities are an independent risk factor for sleep disturbances in cirrhotic patients, highlighting the need for targeted interventions to mitigate muscle abnormalities and potentially enhance sleep quality in this vulnerable population.</p>