Many people wonder if horseradish is a type of radish. After all, it does have "radish" in its name and certain types of radishes do resemble the horseradish root.
However, while both horseradish and radishes are part of the Brassicaceae family of vegetables and they are both roots, they are different species.
Armoracia rusticana is the scientific name for horseradish while the common radish is known as Raphanus sativus.
One thing they do have in common is that both vegetables are usually used just for their roots, when in fact the leaves of both radishes and horseradish are edible. Also, horseradish has a similar appearance to one variety of radish, the Daikon (Raphanus sativus var. longipinnatus). which is a long, white carrot-shaped radish.
Both radishes and horseradish have loads of great health benefits, just like other members in the Brassicaceae group like broccoli, cauliflower, cabbage, and kale. For instance, they all contain sulforaphane, a cancer-fighting compound exclusive to this family of vegetables. Both radishes and horseradish are good sources of sulforaphane (though broccoli sprouts contain the highest levels of the compound).
So the answer is no, horseradish is not a radish but they are in the same family and have some similar qualities and health benefits.