The table below shows the 1989 WTA Tier I Series schedule.
| Details | |
|---|---|
| Duration | March 20 – May 15 |
| Tournaments | 2 |
| Achievements (singles) | |
| Most titles |  Gabriela Sabatini  Steffi Graf (1) |
| Most finals | Gabriela Sabatini (2) |
← 1988 1990 → | |
Singles
edit| Tournament | Surface | Week | Winner | Finalist | Semi finalists | Quarter finalists |
|---|---|---|---|---|---|---|
| Key Biscayne | Hard | March 20 |  Gabriela Sabatini 6–1, 4–6, 6–2 |
 Chris Evert
|
 Helena Suková Zina Garrison Jackson
|
 Isabelle Demongeot  Raffaella Reggi-Concato Jana Novotná  Helen Kelesi
|
| Berlin | Clay | May 15 |  Steffi Graf 6–3, 6–1 |
Gabriela Sabatini
|
Isabel Cueto Helen Kelesi
|
Sandra Cecchini  Barbara Paulus Regina Rajchrtová Sylvia Hanika
|