| 1990 Lufthansa Cup German Open | |
|---|---|
| Date | 14–20 May |
| Edition | 21st |
| Category | Tier I |
| Draw | 56S / 28D |
| Prize money | $500,000 |
| Surface | Clay / outdoor |
| Location | West Berlin, West Germany |
| Venue | Rot-Weiss Tennis Club |
| Champions | |
| Singles | |
 Monica Seles | |
| Doubles | |
 Nicole Provis /  Elna Reinach | |
The 1990 Lufthansa Cup German Open was a women's tennis tournament played on outdoor clay courts at the Rot-Weiss Tennis Club in West Berlin, West Germany that was part of the Tier I category of the 1990 WTA Tour. It was the 21st edition of the tournament and was held from 14 May until 20 May 1990. Second-seeded Monica Seles won the singles title, snapping world no.1 Steffi Graf's 66-match winning streak in the final (2nd in WTA history behind Martina Navratilova's 74-match winning streak).[1]
