Background: Sarcopenia is common in patients with cirrhosis and lower limb muscle strength could represent a factor of morbidity. A systematic review with meta-analysis on knee extension muscle strength in patients with cirrhosis was performed. Methods: Literature was reviewed in electronic databases from inception until March 2023. Two independent researchers applied the inclusion criteria to assess the eligibility of articles. Of the 28 retrieved articles; 21 of them met the eligibility requirements. Results: Muscle strength was impaired in patients with cirrhosis versus age-matched control (standardized mean difference, SMD: 3.48, 95% CI 2.35–4.61, I² = 96.5%, p<0.001) and was negatively influenced by increasing disease severity, with Child-Pugh A and B superior to C (SMD: 2.62, 95% CI 0.54–4.71, p<0.014; SMD 0.71, 95% CI 0.29–1.13, p<0.001, respectively). Exercise training tended to increase (SMD: 1.21, 95% CI 0.16-2.59, p=0.085), while liver transplantation decreased knee extension strength (SMD: -0.45, 95% CI -0.88 -0.01, p=0.045). Conclusion: The negative impact of liver cirrhosis on knee extension strength is worsened by the severity of the disease. Transplantation leads to impaired knee extension strength. Conversely, exercise training tends to be beneficial, making rehabilitation pre and post-transplantation an attractive strategy to prevent muscle mass and strength loss.