He was a key player for the 1974 West Germany national team that won the World Cup (defeating the Netherlands 2–1 in the final, where he provided the assist to the winning goal).

Bonhof was one of the stars for his club side, Borussia Mönchengladbach, and won numerous domestic league and cup titles.

Bonhof was part of the highly successful Borussia Mönchengladbach side of the 1970s, winning numerous Bundesliga, DFB-Pokal, and UEFA Cup titles.

Bonhof played in every match of the 1978 FIFA World Cup when West Germany was eliminated in the second round following a 3–2 defeat at the hands of their historic rivals, Austria.

His move and that of Uli Stielike prompted the DFB to remove their ban on selecting foreign based players for the national team.

He played a role in qualifying for the 1980 European Championships and was selected for the squad, but injuries kept him from making an appearance during the West German victory.

Former Liverpool goalkeeper, Ray Clemence, in 1977, following a European Cup final between the Reds and Borussia Mönchengladbach, admitted he feared Bonhof's shots.

His fear was to prove justified, as during the spring of 1978 Clemence was beaten twice by Bonhof from nearly identical locations at both club and international level.

[4][6] On 1 September 2006, Bonhof signed a contract with recent FA Premier League winners Chelsea to become their scout for the scopes of Germany and Austria.