Swietenia mahagoni seed has been traditionally used as a wound healing agent. The aim of this study was to investigate the in vitro healing properties of Swietenia mahagoni seed extract. A supercritical carbon dioxide (SCCO2) extract of Swietenia mahagoni seeds was tested regarding its ability to stimulate the growth of human skin fibroblasts (HSF 1184) in vitro using the colorimetric methylthiazol tetrazolium (MTT) assay and scratch assay in a selected range of extract concentrations. The results show that the Swietenia mahagoni seed extract at a concentration of 0.01 mg/mL was able to stimulate the growth of human skin fibroblasts. The scratch assay showed that all of the extracts led to a significantly higher percentage of wound closure compared to the control. The wound healing capabilities of Swietenia mahagoni seed extract may be due to its fibroblast stimulation activity, which may promote repair of the wounded dermis. Thus, it may serve as a good herbal component to incorporate into products designed to promote wound healing.