['To determine if having a night-time nurse-to-patient ratio (NNPR) of one nurse caring for one or two patients (> 1:2) versus one nurse caring for three or more patients (< 1:2) in the intensive care unit (ICU) is associated with clinical and economic outcomes following esophageal resection.', 'State-wide observational cohort study. Hospital discharge data was linked to a prospective survey of ICU organizational characteristics. Multivariate analysis adjusting for case-mix, hospital and surgeon volume was used to determine the association of NNPR with in-hospital mortality, length of stay (LOS), hospital cost and specific postoperative complications.', 'Non-federal acute care hospitals (n = 35) in Maryland that performed esophageal resection.', 'Adult patients who had esophageal resection in Maryland, 1994 to 1998 (n = 366 patients).', 'Two hundred twenty-five patients at nine hospitals had a NNPR > 1:2;128 patients in 23 hospitals had a NNPR < 1:2. No significant association between NNPR and in-hospital mortality was seen. A 39 % increase in median in-hospital LOS (4.3 days; 95% CI, (2, 5 days); p < 0.001), and a 32% increase in costs ($4,810; 95 % CI, ($2,094, $7,952) was associated with a NNPR < 1:2. Pneumonia (OR 2.4; 95 % CI (1.2, 4.7); p = 0.012), reintubation (OR 2.6; 95% CI(1.4, 4.5);p = 0.001), and septicemia (OR 3.6; 95 % CI(1.1, 12.5); p = 0.04), were specific complications associated with a NNPR < 1:2.'] Is iCU nurse-to-patient ratio associated with complications and resource use after esophagectomy?