An outbreak caused by the novel swine-origin influenza A (H1N1) virus was identified in Mexico in late March 2009. The objective of this report is to describe the organization of a tertiary care center in Mexico City during the contingency. We describe the education program, the hospital organization and triaging, and unforeseen overwhelming circumstances. Educational plans were directed to follow standard, contact, and droplet precautions and to condition behavior to avoid touching the eyes, nose, or mouth. N95 respirators were distributed only to perform respiratory procedures. By the fifth month into the epidemic, four patients with hospital-acquired influenza, 467 workers with respiratory symptoms suggestive of influenza (16% of our staff), and 96 workers with confirmed novel influenza A (3% of our staff) were identified. During the first 2 months of the epidemic, 44,225 people went through the triages and only 1503 (3.3%) reached the emergency room. By the fifth month into the epidemic, four small institutional influenza outbreaks (<10 workers each) had been identified, two of them in areas with no patient contact. Molecular testing for influenza was used mainly for epidemiological purposes. Even though we had a supply, we had difficulties in meeting the demand of masks, N-95 respirators, and hand sanitizers. Due to absenteeism, the nursing administration experienced difficulties in covering shifts. Preparation is mandatory for facing an influenza epidemic. The correct use of precautions is an economic measure to limit institutional transmission. Adequate triaging is essential to meet unusual attention demands.