Mesenchymal stromal cells (MSCs) have been among the most intensively studied cells in recent years. Lack of specific unique markers for these cells makes it difficult to distinguish MSCs from other types of cells, such as fibroblasts or pericytes. MSCs are a mixture of morphologically different cells with expression of various cellular markers, with varying degrees of differentiation, as well as varying proliferation capacities. The majority of phenotypic features of these cells have been identified through cell culture. One of their basic features is the capacity to differentiate into three cell lines: osteoblasts, adipocytes and chondroblasts. Under in vivo conditions, MSCs form an important functional element of the hematopoietic stem cell niche. Residing within the blood vessel wall, MSCs assist in its formation and functioning. MSCs release anti‑apoptotic and pro‑angiogenic factors, as well as agents that stimulate cell proliferation and also immunostimulating factors. In this study, we focused in particular on therapeutic strategies employing MSCs to improve the performance of the infarcted heart as well as on their involvement in the repair of hard-to-heal wounds. Thanks to the released anti-inflammatory agents, MSCs can inhibit inflammatory reactions. Owing to cytokines and growth factors they can also stimulate regeneration of damaged tissues and organs. The therapeutic effect that follows MSCs administration is linked to their paracrine activity.