Introduction Frailty and sarcopenia associate with increased mortality in patients with liver cirrhosis on the transplant waitlist. We conducted a systematic review on the impact of pretransplant frailty and sarcopenia on post-transplant outcomes in adult patients with liver cirrhosis. Methods We performed a search in Medline , Embase and Cochrane Central . Of the 12276 references initially recovered, 34 were included. Results Frailty and sarcopenia presented a negative impact on post-transplant outcomes and seemed to associate with an overall two-fold reduction in early and 50% reduction in late survival, for severe conditions, according to the largest cohorts. These patients required longer ICU and hospitalization time, had higher rates of sepsis and respiratory complications and lower graft-survival. The reversibility of frailty depended on the severity of functional impairment and on the co-morbidities contributing to frailty. Reversibility of sarcopenia occurred in only a minority of patients, in unbiased studies. Conclusion Frailty and sarcopenia are double-edged swords: patients with frailty/sarcopenia should be prioritized for liver transplantation due to increased mortality on the waitlist; however, severe frailty/sarcopenia may justify delisting because it associates with dismal prognosis post-liver transplantation. Patients presenting mild to moderate frailty/sarcopenia, should be submitted to liver transplantation before those conditions worsen to a level that significantly impacts post-liver transplantation outcomes.