Introduction: Consultation-liaison psychiatry (LS), is a multidisciplinary subspecialty of psychiatry, which becomes applicable in the context of the function of the general hospital. As it has evolved greatly in the last century, having made significant changes in the way diseases are treated and also by offering significant benefits to the health system and its users, as well as to the staff working in it, we will try in this review to evaluate the expected benefits of the LS services in the general hospital. Aim: The purpose of this study, was to evaluate the expected benefits of the LS services in the general hospital and more specifically, the significantly or not, overall limited health care cost, the reduced lengths of stay and the reduction of the admissions and re-admissions of patients arriving to the emergency department. Method: The methodology of this study was a literature review, during the period of time from 1980 to 2020, in databases such as Pubmed & Google Scholar, by using keywords such: Liaison psychiatry services, acute general hospitals, lengths of stay, cost-effectiveness, admissions, readmissions. A total of 180 studies were found, of which only 12 were consistent with the review subject and they were finally used. Results: In total, 8 studies identified benefits of LS in terms of hospitalization, admissions and re-admissions, which resulted in reduced health care costs. In contrast, 2 studies presented negative findings regarding the contribution of LS during hospitalization, while another 2 studies failed to show overall financial benefits in the general hospital, neither in the under consideration parameters, nor in further. Conclusions: It seems that from the expected benefits of LS which, have been studied in the long term, a positive evaluation regarding its contribution to the general hospital continues to emerge. That is why we consider it is a useful and supportive service, which must continue to exist, be further studied and improved where needed.