Osteoarthritis (OA) is the most common form of arthritis that affects cartilage joints and leads to disability. OA becomes the major public health problem, as it is the most leading cause of disability and morbidity worldwide. Treatment choices for OA can be classified into several categories such as non-pharmacologic, pharmacologic, surgical therapy, and cell-based therapy. There is no curative treatment for OA, while conventional treatments that are commonly used focus on alleviating the pain as the main symptom of the disease. Mesenchymal stem cells (MSCs) that can be found in several tissues of human body offer a new strategy for OA treatment owing to their ability to differentiate into chondrocytes. This article provides an overview about the basic concept of osteoarthritis as well as an insight about the MSCs therapy, including their basic characteristics, source, and transplantation strategies in the OA area.