Martenstein studied History and Romance Studies in Freiburg. From 1981 to 1988, he was a journalist at the Stuttgarter Zeitung and from 1988 to 1997 he was a journalist at Tagesspiegel in Berlin. Then, Martenstein took up for a short time the line of the culture editorship at the Abendzeitung (AZ) in Munich. However, he returned a little later as senior editor to the Tagesspiegel. Since 2002, he has written a column for Die Zeit titled "Lebenszeichen", which since May 24, 2007 appears in Zeit-Magazin LEBEN (a supplement to Die Zeit) as "Harald Martenstein". Since 2004 Martenstein also writes a column for GEO Kompakt.