She represented Finland at five Olympic Games and won bronze medals in the women's ice hockey tournaments in 1998 and 2010. She has also represented Finland at thirteen IIHF World Women's Championships and has earned eight World Championship bronze medals (1997, 1999, 2000, 2004, 2008, 2009, 2011, 2015). Rantamäki has played with national championship winning teams in both the Naisten Liiga in Finland and the Zhenskaya Hockey League (ZhHL) in Russia and its predecessor, the Russian Women's Hockey League.