Objective. To measure the impact of the pandemic in Spanish ICUs. Material and methods. On-line survey, conducted in April 2021, among SEMICYUC members. Participants were asked about number of patients admitted, increase in the number of beds and staff, structures created in the hospital and self-assessment of the work performed. Results. We received 246 answers from 157 hospitals. 67.7% of the ICUs were expanded during the pandemic, overall increase in beds of 58.6%. The ICU medical staff increased by 6.1% and there has been a nursing shortage in 93.7% of units. Patients exceeded 200% the pre-pandemic ICU capacity. In 88% of the hospitals the collaboration of other specialists was necessary. The predominant collaboration model consisted of the intensive care medicine specialist being responsible for triage and coordinating patient management. Despite that 53.2% centres offered training for critical care, a deterioration in the quality of care was perceived. 84.2% hospitals drew up a Contingency Plan and in 77.8% of the hospitals a multidisciplinary committee was set up to agree on decision-making. Self-evaluation of the work performed was outstanding and 91.9% felt proud of what they had achieved, however, up to 15% considered leaving their job. Conclusions. The Spanish ICUs assumed an unprecedented increase in the number of patients. They achieved it without hardly increasing their staff and, while intensive care medicine training was carried out for other specialists who collaborated. The degree of job satisfaction was consistent with pre-pandemic levels.