In the 1988 Seoul Games, Wallrodt won two gold medals in the Men's Shot Put 2 and the Men's Javelin 2 events, and a bronze medal in the Men's Discus 2 event. At the 1990 World Championships and Games for the Disabled in Assen, Netherlands he won gold medals in the Men's Shot Put and Discus F4 events. At the 1992 Barcelona Games, he won a gold medal in the Men's Javelin THW4 event (for which he received a Medal of The Order of Australia), and two silver medals in the Men's Discus THW4 and the Men's Shot Put THW4 events. Going into the 1992 Games, he was a world record holder in discus, javelin and shot put. In the 1996 Atlanta Games, he won a gold medal in the Men's Shot Put F53 event, in which he broke a world record, and a bronze medal in the Men's Javelin F53 event. In 2000, he received an Australian Sports Medal. He won a silver medal at the 2000 Sydney Games in the men's shot put T54 event and came 4th in the Men's Javelin F54 – event. At the 2004 Athens Games, he came fifth in both the Men's Javelin F54 and the Men's Shot Put F54 events.