The metabolic response to complete spinal cord injury was prospectively studied in 10 patients with Frankel class A spinal cord injury. Weekly excretory and balance studies profile the changes in nitrogen, calcium, and 3‐methylhistidine excretion in relation to body weight and metabolic rate. The initial resting energy expenditures were 10% below what was predicted, and body weight decreased by 10%. Nitrogen excretion paralleled the changes in body weight. Calcium excretion increased for 3 weeks and reached a plateau 150% above baseline. Our results chronicle the magnitude of metabolic response to spinal shock. Comparison with reported values shows this response exceeds that seen in immobilized patients. Nitrogen excretion rose to levels seen in highly stressed patients and must be considered in the management of patients with acute spinal‐cord injury.(Journal of Parenteral and Enteral Nutrition16:11–15, 1992)