That December, she went to LPGA Qualifying School. By the end of the week, she was one of four players left playing for the final two full membership cards. They played three holes to determine their fate. Choi birdied the first, and after three holes, had the lead; one of the two cards was hers! Thus, she became a rookie on tour in 2009.

In 2009, Choi worked hard to gain full status, but in the end just fell short, finishing 86th on the year end money list. Her best finish was a 20th at the LPGA Tour Championship Presented by Rolex.

Choi's record improved in 2010 when she earned category 1 status for 2011. The year that followed brought her over $325,000,000 in prize money and significant signs of improvement on the circuit as Chella recorded two top ten finishes - at the Walmart NW Arkansas Championship Presented By P&G (T10th) and the LPGA Hana Bank Championship (7th).

In 2011 Chella Choi finished tied for 12th at the Kia Classic; tied for 13th at the US Women's Open; tied for 13th at the Safeway Classic Presented by Coca-Cola; tied for 22nd at the RR Donnelley LPGA Founders Cup; tied for 23rd at the Avnet LPGA Classic and tied for 25th at the Evian Masters.

Choi enjoyed a successful 2012 making 23 cuts from 27 events including a career high T-2 finish at the 2012 Manulife Financial LPGA Classic where she lost in a four-way, three-hole sudden death playoff.