A multivariate analysis of the prognostic factors for clinical Stages I and II supradiaphragmatic Hodgkin's disease was carried out with a logistic regression model in 341 patients. The proportion of patients with positive staging laparotomy was greater in males, in individuals with several sites involved, mixed cellularity (MC) or lymphocyte depletion (LD) histologic types, systemic symptoms, or in patients with lower cervical involvement and higher erythrocyte sedimentation rate (ESR), serum copper, and LDH levels. Histology, presence of systemic symptoms (fever and sweats), and number of involved nodal regions were independent predictors of positive laparotomy. Mediastinal involvement is correlated to a significantly lower risk of positive laparotomy. Based on these observations, the individual risk for each patient of occult abdominal disease has been defined.