Mesenchymal stem cells (MSCs) have a wide range of therapeutic potential including anti-inflammatory, immunomodulatory and neuroprotective effects. However, few studies have used a model of partial sciatic nerve ligation (PSNL) to analyze the effects of human MSCs on neuropathic pain, which is difficult to control with any analgesics available. Therefore, the aim of this study is to examine the effects of MSCs from human adipose (AD-MSC) and umbilical cord (UC-MSC) on the neuropathic pain, and to elucidate its mechanisms using this PSNL model. We found that a single intravenous administration of AD- or UC-MSCs significantly improved both the mechanical threshold determined by the von Frey test and imbalanced walking of the left and right hind paws with the weight-bearing test. These anti-nociceptive effects of MSCs lasted for at least 7 days. MSCs from both sources significantly decreased PSNL-induced expression of Iba-1 and IL-1β in the dorsal root ganglia. In addition, the MSCs significantly restored the PSNL-induced reduction in the myelin basic protein levels in sciatic nerve isolated from PSNL-exposed rats. These results suggest that AD- and UC-MSCs could improve neuropathic pain via anti-inflammatory actions and remyelination.