The 2009 Copa Petrobras Buenos Aires was a professional tennis tournament played on outdoor clay courts. It was part of the 2009 ATP Challenger Tour. It took place in Buenos Aires, Argentina between 28 September and 4 October 2009.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Argentina | Horacio Zeballos | 58 | 1 | |
| Argentina | Máximo González | 67 | 2 | |
| Nicolás Massú | 96 | 3 | ||
| Argentina | Juan Ignacio Chela | 111 | 4 | |
 Spain | Santiago Ventura | 112 | 5 | |
| Argentina | Sergio Roitman | 124 | 6 | |
| Spain | Rubén Ramírez Hidalgo | 125 | 7 | |
 France | Laurent Recouderc | 132 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
Carlos Berlocq Alejandro Fabbri Andrés Molteni Lionel NoviskiSee main article: 2009 Copa Petrobras Buenos Aires – Singles. Horacio Zeballos def. Gastón Gaudio, 6–2, 3–6, 6–3
See main article: 2009 Copa Petrobras Buenos Aires – Doubles. Brian Dabul / Sergio Roitman def. Máximo González / Lucas Arnold Ker, 6–4, 7–5