Mónica Saez starts for the EMEM military sports club . In 2008 she won her first medal at the Spanish Biathlon Championships with bronze in the sprint . In 2009 she won her first titles in the sprint and pursuit races in the summer biathlon . In 2010, she was runner-up in sprint and pursuit in both winter and summer. In 2013, Saez won her first winter title in the pursuit after being runner-up in the sprint. In 2014 he won both titles, individual and sprint, at the summer biathlon championships.
In 2009 and 2010, Saez also took part in the cross-country skiing championships and just missed a medal in 2010 in the 10-kilometer freestyle as fourth.