Organ transplantation continues to be the gold standard for saving the lives of patients with end-stage organ diseases. Its goal is to help recipients live longer and better lives. However, despite advancements, organ transplantation still faces serious challenges, such as organ shortage and the effects of chronic immunosuppression. In this regard, there is ongoing vigorous search for therapeutic strategies that can improve the efficacy of allogeneic organ transplantation. Mesenchymal stems cells (MSCs) can significantly enhance and accelerate regenerative processes in damaged organs, can angiogenesis angiogenesis and inhibit cell apoptosis, inflammation and fibrosis formation, and have immunomodulatory properties. Researchers and physicians are interested in MSCs because of a set of unique properties that could be useful in solid organ transplantation. This review critically analyzes and summarizes the actual clinical data related to the study of the therapeutic effects of MSCs in organ transplantation. Electronic databases Medline/PubMed (www/ncbi.nlm.nih.gov/pubmed) and eLIBRARY/Russian Science Citation Index (https://www.elibrary.ru) were searched for relevant literature. Inclusion criteria were clinical use of MSCs to improve the condition of kidney, liver, lung, heart and pancreas recipients, and to enhance graft quality. Exclusion criteria for articles included the use of MSCs for the treatment of non-transplant patients, as well as articles detailing the effects of MSCs products (exosomes, vesicles and conditioned media) and research studies conducted in vitro and in vivo (without patient participation), conference proceedings, reviews and preprints of articles. Thirty-one original articles in English and Russian languages were selected for literature review. The prospects of MSCs in transplantology are also covered in the paper.