Q. Is it wrong for a father and son to have the same first name?
A. It was certainly done in ancient times. The Apocrypha records that Tobit called his son Tobias: “When I came of age I took a wife from our kindred, and had a son by her whom I named Tobias” (Tobit 1:9).
Josephus had a brother whose name was Matityahu ben Matityahu: “I was born to Matityahu… I was brought up with my brother, whose name was Matityahu” (Life of Flavius Josephus 1, 2). Elsewhere Josephus refers to Chananiah ben Chananiah and Yochanan ben Yochanan (Antiquities 20:9:2, 10:1:2). Talmudic literature refers to Chanina ben Chanina, Bonias ben Bonias, Leizer ben Leizer, Yosef ben Yosef, Chiyya ben Chiyya, Ba bar Ba, etc.
The custom was and is maintained by the Sephardim, but the Ashkenazim prefer not to name a child after a living relative. Sometimes an Ashkenazi child is given his father’s first name if the father has already died.