Highlights:1. This study determined the toxic effects of combining Caesalpinia sappan and Zingiber officinale extracts, aspeople need to be aware of the potential side effects of these common herbal remedies for the treatment ofrheumatoid arthritis.2. The combination of Caesalpinia sappan and Zingiber officinale extracts is efficacious and non-toxic as an antiarthritis treatment, hence, the ingredients can be upgraded to standardized herbal medicines andphytopharmaceuticals. Abstract Sappanwood (Caesalpinia sappan) and red ginger (Zingiber officinale) are plant species that have been studied for theirefficacy in treating inflammation related to rheumatoid arthritis. This study aimed to examine the effects of combiningsappanwood and red ginger in order to determine the potential toxicity of the herbal extracts in medicine. The toxicitytesting was carried out in vivo using 32 Wistar strain male white rats (Rattus norvegicus) grouped into eight groups of four.The rats were injected with complete Freund's adjuvant to induce a chronic inflammatory effect. The eight groups consistedof the negative control group, the positive control group, the normal group, and five treatment groups. This study wasconducted by observing the animals for toxic symptoms and death to determine the safety of the extracts and drugs. Theobservation results were analyzed using a one-way analysis of variance (p<0.05). The analysis results showed that weightgain and relative organ weight among the groups had no significant differences (p>0.05). Microscopic examination of theorgan preparations observed under a light microscope revealed no significant changes or adverse effects in rats treated withthe extracts or drugs. In conclusion, a combination of sappanwood and red ginger ethanol extracts administered orally hasno toxic effect in rats injected with complete Freund's adjuvant.