All indications of linezolid (LZD) in Intensive Care Units (ICU) were included as cases in an observational, prospective and multicentre study. One hundred thirty-nine indications were analyzed. In most cases (92.7%), treatment for nosocomial infections was indicated. The most frequent infection was pneumonia (42.7%), followed by catheter-related bacteraemias (CRB). A total of 58.7% of the indications were empirical and in 45.7% of the cases the cultures confirmed infection by gram-positive cocci (GPC). In 43 cases (31.2%), the indication was made as a rescue measure (mainly due to clinical failure) in patients previously treated with glycopeptides. Of isolated GPC, 70.2% were methicillin-resistant. The cure rate of the population per intent-to-treat was 73.2%. Only one case of thrombocytopenia was recorded. Conclusions. LZD is used with a high degree of diagnostic safety. In the ICU, it is primarily indicated to treat pneumonias and CRB with good clinical and microbiological response. This antibiotic has acted as a good therapeutic resource against clinical failure in infections treated with glycopeptides.