As there have been strong interests in finding traditional agents that may help in the prevention of inflammation and disruption of neural tissues in CNS, a well-known herbal drug which has exhibited antioxidant and neuroprotective effects is Melissa officinalis (MO). MO is commonly known as lemon balm (family: Lamiaceae); it is one of the oldest and still the most common medicinal plants (Kamdem et al., 2013). It has been reported that the most commonly known therapeutic properties of MO extract were sedative, antispasmodic, carminative, antibacterial, antiviral, antiinﬂammatory, antioxidant, as well as neuroprotective (Kamdem et al., 2013). It was previously shown that the effective dose of MO was 150 mg/kg in SCI contusive model, and it was also shown that MO extract was effective in improving motor, sensory, and cellular function after injury (Hosseini et al., 2015). Therefore, the aim of this study is to assess the effectiveness of the MO extract in combination with hUCBSC transplantation after contusive SCI in Wistar rats. It was hypothesized that the combination of MO and hUCBSCs may play a role in preventing harmful effects and neural damage triggered by SCI.