Identical quintuplets are possible, though the closest possibly identical quints were born in Poland in 2008, according to About.com. The only known identical quintuplets prior to that were the Dionne sisters, who were born in Ontario, Canada in 1934.
The odds of having identical quintuplets are estimated to be 1 in 15 million, according to About.com. Multiple embryos created via assisted reproductive technology are not uncommon, but these embryos are more commonly multizygotic, or fraternal embryos. Multiple embryos from the same egg are called monozygotic. Due to the rarity of multiple births from natural methods, it is almost unheard of to have monozygotic babies beyond twins or triplets.