Rosary tattoos are usually seen on people who are Roman Catholic, and who want to show off their faith or Christian values. While some religions, specifically Judaism and Islam, denounce tattoos and do not allow their followers to get inked, not all religions have specific rules about tattoos. There are often different sentiments expressed by Catholics and Protestants about the allowance of tattoos in their churches.
Both Christians and Jews abide by the Bible, and feel that there is a passage in the Old Testament that specifically prohibits tattoos: "Do not cut your bodies for the dead or put tattoo marks on yourselves. I am the Lord." - Leviticus 19:28 Depending on how strictly you interpret the Bible, this can be seen as a full-on denouncing of tattoos, or just a warning against specific marks from Biblical times. Jews proclaim that this statement means any tattoos on human skin are forbidden, while some Christians do not take the quote as literally.
Today, some churchgoers feel ink, such as Rosary tattoos, are not attractive, but others see getting tattoos such as those of the Rosary and crosses to be a welcome sign of faith.
Source : http://tattoos.lovetoknow.com/Rosary_Tattoos