Yes, swiss chard is high in oxalates. Oxalates are natural chemicals found in plants that can bind to minerals like calcium, magnesium, and potassium. When these minerals are bound to oxalates, they can't be absorbed by the body. This can lead to deficiencies in these minerals. For this reason, people with kidney stones or other health conditions that affect their ability to absorb minerals should avoid eating high levels of oxalates. However, for most people, the benefits of eating swiss chard outweigh the risks posed by its high oxalate content.