Aristolochic acids are a family of carcinogenic, mutagenic, and nephrotoxic phytochemicals commonly found in the flowering plant family Aristolochiaceae. Aristolochic acid I is the most abundant one.

The Aristolochiaceae are a family, the birthwort family, of flowering plants with eight genera and about 400 known species belonging to the order Piperales. The type genus is Aristolochia L.