Rämö was drafted with the 191st overall pick by the Tampa Bay Lightning in the 2004 NHL Entry Draft. He made his NHL debut with the Lightning on December 2, 2006 in a 5–2 loss to the Ottawa Senators. Rämö won his first NHL start on December 20, 2006 in a 2–1 victory against the Toronto Maple Leafs. On August 16, 2010, he was traded to the Montreal Canadiens in exchange for Cédrick Desjardins. He however decided to play for Avangard Omsk of the Kontinental Hockey League (KHL). On January 12, 2012, The Canadiens traded him along with Michael Cammalleri and a 5th-round pick in the 2012 NHL Entry Draft to the Calgary Flames for René Bourque, Patrick Holland and a 2nd-round pick in the 2013 NHL Entry Draft.