The serum LDH level determined at time of diagnosis provides important prognostic information about patients with Hodgkin's disease. The median survival of patients with a normal value was 129 months, whereas those with elevated values had a median survival of only 39 months. The prognostic power of LDH persisted after adjustment for age, symptom class, stage, or histology. When the Cox proportional hazards regression method was used to simultaneously adjust for age, histology, symptom class, and stage, elevated enzyme levels still were correlated with short survival. (J Lab Clin Med 99:382, 1982.)