1990 ATP German Open

The 1990 German Open was a men's tennis tournament played on outdoor clay courts. It was the 84th edition of the Hamburg Masters (Hamburg Masters), and was part of the ATP Super 9 of the 1990 ATP Tour. It took place at the Rothenbaum Tennis Center in Hamburg, West Germany, from 7 May through 14 May 1990.

The men's field was headlined by ATP No. 3, Brussels, Stuttgart titlist, Australian Open, Monte Carlo quarter-finalist Boris Becker, Miami, San Francisco winner, recent Indian Wells finalist Andre Agassi and Tokyo Outdoor winner and U.S. Open semi-finalist Aaron Krickstein. Other top seeds were Estoril titlist Emilio Sánchez, Jay Berger, Andrés Gómez and Michael Chang.

Singles
🇪🇸 Juan Aguilera defeated 🇩🇪 Boris Becker, 6–1, 6–0, 7–6(9–7),
 * It was Juan Aguilera's 2nd title of the year, and his 5th overall. It was his 1st Masters title of the year, and overall.

Doubles
🇪🇸 Sergi Bruguera / 🇺🇸 Jim Courier defeated 🇩🇪 Udo Riglewski / 🇩🇪 Michael Stich, 7–6, 6–2