Lewis's 1990 Commonwealth Games gold medals were in the 200m freestyle, the 400m freestyle, the 200m butterfly, 400m individual medley and the 4X200 free relay. She also won bronze in the 200m individual medley.
At the 1991 World Championships in Perth she won gold in the 200m freestyle, silver in the 400m freestyle, silver in the 400m individual medley, and bronze in the 200m butterfly.
For the rest of her career, Lewis focused on the 800m freestyle, in which her best Olympic result was a silver medal at the 1992 Summer Olympics and a silver at the 1994 Rome World Championships. She also won a bronze medal in the 400m freestyle in Barcelona. At the 2001 World Aquatics Championships, Lewis won a bronze medal in the 5 km Open Water competition. She had planned to attempt to qualify for the 10 km open water event at the 2004 Summer Olympics, but this event was removed from the competition. She competed at three Olympics.
Lewis is the current host of the Australian version of The Biggest Loser and has been since the 5th season. She started the first swimming centre based inside a major shopping centre within Australia in 2002 at Westfield Carindale in Brisbane. In September 2010, Westfield's redevelopment plans saw Lewis's pool demolished. She now owns the well-known Brisbane gift and homewares store, Coming Up Roses. In April 2011, Random House published Hayley's first business book, Dream Believe Create. She married her childhood sweetheart, Greg Taylor, in 1997 and they have two sons, Jacob and Kai.
She is also a regular contributor to entertainment and lifestyle website Live4.