Arno Ehret was a member of the West German handball team that lost the match for the bronze medal 21-18 against Poland after extra time at the 1976 Montréal Olympics. He earned 121 international caps scoring 308 goals. In 1978, Ehret was on the West German national team winning the World Championship, 29-24, against Poland. Domestically, he played with TuS Hofweier and was elected Handball Player of the Year in 1980. In 1979 and 1981 he became the leading scorer of the 1. Bundesliga.
After his active career Ehret turned to coaching and coached his home club from 1982-85. Further coaching stations in Germany were TuS Schutterwald (1985-86), TSV Bayer Dormagen (1990), and VfL Gummersbach (1999-2000). He also had two stints as Swiss chief national coach from 1986-93 and from 2000-06, and he coached the German national team from 1993-97. Since 2013 he worked with different clubs in Switzerland. By profession, he was a sports and mathematics teacher.