What is henna tattooing? Henna tattooing is a form of temporary body decoration similar in appearance to a tattoo and it last on the skin from 7 to 10 days. Henna tattoos are becoming very popular, for many people, committing themselves to a single permanent tattoo is somewhat intimidating. However, there is an alternative. Henna tattoos are a form of temporary body art that has been practiced for millennia (but has only become popular in the United States within the last few decades). Also, it is known as Mehndi.