Acquired lymphedema is a pathological condition associated with lymphatic dysfunction caused by surgical treatments for cancer. Although global estimates of the prevalence of acquired lymphedema have been rising, there are currently no effective therapeutics available. Since adipose tissue accumulation is a clinical hallmark of lymphedema, we hypothesized that regulation of adipogenesis in lymphedematous tissue could be used as a therapeutic intervention against lymphedema. Toward this, we investigated the possibility of anti-adipogenic 30% ethanol Rhus verniciflua Stokes (RVS) extract as a potential lymphedema treatment. Oral administration of RVS extract ameliorated volumetric symptoms of lymphedema in a mouse model. RVS administration also reduced adipose tissue accumulation in lymphedematous tissue and downregulated expression of adipocyte markers, including Pparγ and Fabp4. Sulfuretin was identified as a major bioactive compound in the 30% ethanol RVS extract in liquid chromatography-mass spectrometry analysis. Similar to the activities of RVS, sulfuretin inhibited adipocyte differentiation in 3T3-L1 preadipocytes. Moreover, treatment with sulfuretin on lymphedema-induced mice reduced lymphedema volume, decreased the expression of adipogenic markers, but induced the expression of markers associated with lymphangiogenesis. Taken together, our data raise the possibility that sulfuretin might be used in therapeutic interventions against acquired lymphedema.