We conducted a prospectively controlled study of adjuvant immunochemotherapy for resectable lung cancer in 37 cases of the control group, in 34 cases of levamisole group and in 40 cases of OK-432 group. No significant difference was noted in patient characteristics of age, sex, histological type, stage, cure rate, etc. The survival rates were calculated by Kaplan and Meier method. Survival curves were measured by generalized Wilcoxon test and Cox-Mantel test. When the levamisole group and the control group were compared in terms of survival rate, a significant increase of survival curves of patients treated with levamisole was observed in surgicopathological stage III + IV and relative curative operation groups (p less than 0.05). The survival rate of levamisole group was higher than that of OK-432 group in patients of surgicopathological stage III and III + IV (p less than 0.05). There was no statistically significant difference between OK-432 group and the control group, when in survival rates.