Claudia Poll began swimming in 1979 under coach Francisco Rivas and quickly became one of the best in Central America, winning many regional titles.

At the 1996 Atlanta Olympics she won the Gold medal in the 200 m Freestyle event. The win was the first gold medal for Costa Rica in a summer Olympic game. It was a surprising win because she snatched the medal from the favorite Germany's Franziska Van Almsick. Dagmar Hase, also from Germany won the bronze.

In 1997, she was named by Swimming World Magazine as the Female Swimmer of the Year.

At the Sydney 2000, Poll continued with her medal run and won 2 bronze medals. In Athens 2004, she just missed out on the 400 m Freestyle final, ending up 9th on the time table.

At the 2006 Central American and Caribbean Games, she set the Games Records in the 200 & 400 frees (2:00.19 and 4:15.01), bettering the time her sister Silvia set at the 1986 Central American and Caribbean Games.

Claudia was accused of doping in 2002. She appealed the verdict but on 3 June 2002, the Court of Arbitration for Sport (CAS) dismissed the appeal against the decision of the FINA Doping Panel and decided to sanction her for a positive out-of-competition doping control with nandrolone metabolites, with a 4 year suspension.[citation needed] The 4 year suspension was later reduced to 2 years in the course of harmonization of FINA and WADA doping rules. To this day Claudia still defends her innocence.

Claudia graduated in Business Administration from the Universidad Internacional de las Américas, San José, Costa Rica, in 1998. Poll became a mother for the first time on August 8, 2007. Her daughter's name is Cecilia. Claudia's older sister Silvia Poll Ahrens was also a competitor swimmer who won a silver medal in 1988, Costa Rica's first-ever Olympic medal.

1968: Debbie Meyer | 1972: Shane Gould | 1976: Kornelia Ender | 1980: Barbara Krause | 1984: Mary Wayte | 1988: Heike Friedrich | 1992: Nicole Haislett | 1996: Claudia Poll | 2000: Susie O'Neill | 2004: Camelia Potec | 2008: Federica Pellegrini

 1973: Keena Rothhammer (USA)  •  1975: Shirley Babashoff (USA)  •  1978: Cynthia Woodhead (USA)  •  1982: Annemarie Verstappen (NED)  •  1986: Heike Friedrich (GDR)  •  1991: Hayley Lewis (AUS)  •  1994: Franziska Van Almsick (GER)  •  1998: Claudia Poll (CRC)  •  2001: Giaan Rooney (AUS)  •  2003: Alena Popchanka (BLR)  •  2005: Solenne Figuès (FRA)  •  2007: Laure Manaudou (FRA)  •  2009: Federica Pellegrini (ITA)

 1985: Carrie Steinseifer (USA) •  1987: Mitzi Kremer (USA) •  1989: Patricia Noall (CAN) •  1991: Nicole Haislett (USA) •  1993: Claudia Poll (CRC) •  1995: Suzu Chiba (JPN) •  1997: Claudia Poll (CRC) •  1999: Susie O'Neill (AUS) •  2002: Lindsay Benko (USA) •  2006: Katie Hoff (USA)