In 1989, after graduating in journalism, Sandra moved to London and began to work as a photojournalist. In 1991 she covered the outbreak of the war in Croatia as a stringer for The Times. Until the end of 2000, much of her work was done in the Balkans, where she covered the most significant events of the series of armed conflicts, contributing to various Spanish and international publications. She has also produced important reportages from Israel, Palestine, Mexico, Rumania, Canada, Cuba, Mozambique, Haiti, and Italy (Sicily and Lampedusa).
She is the author of the book Balkan in memoriam (Blume, 2002), an extensive photographic exploration of the most convulsive decade in the history of the former Yugoslavia, and co-author of Montreal métropole: vue par 30 grands reporters (Aux Yeux du Monde, 2000). She is also the co-creator of the television documentaries Dying for the Truth (Channel 4, 1994) and Retratos del alma (TVC, 2004).
Awarded the Premio Ortega y Gasset in 2006 for Best Informative Work, she has participated in more than fifty individual and collective exhibitions and her work can be found in various public and private collections. Over the past decade she has curated several photography exhibitions, including Latidos de un mundo convulso (2007), Desaparecidos (2011), and Antología–Gervasio Sánchez (2012). Since 1995 she has combined her work as a journalist with teaching at the Universitat Ramon Llull.