An attempt was made to assess the immunological importance of regional lymph node histology in relation to the survival of 107 patients with carcinoma of the larynx, operated on from 1973 to 1982 at the ENT-Clinic in Marburg. A total of 2765 sections of lymph nodes removed during neck dissections were examined microscopically to evaluate the morphological patterns of response. Microscopically, four distinct patterns were defined. Patients whose lymph nodes demonstrated immunological responses according to patterns I and II in the form of either expanded inner cortices or increased numbers of germinal centers had a greater 5-year survival rate than those patients whose lymph nodes showed an unstimulated pattern. Eight patients whose lymph nodes showed a depleted pattern, IV, did not survive more than 3 years. Morphological assessment of immunological activity in lymph nodes draining malignant tumors seems to be of value in predicting survival. The evaluation of the reaction pattern and difficulties in methodology, however, set definite limitations to our study.