The purpose of this study was to look for effects of attachment styles for emotional reacting with depression in 117 lung cancer patients who were undergoing surgery during hospitalization and six weeks later. All subjects were classified according to their attachment style (secure, avoidant, ambivalent) assessed by means of the instrument based on Hazan and Shaver's (1987) descriptions of how people typically feel in close relationships. The Beck Depression Inventory was used to measure depression. Anova variance analysis revealed higher level of depression in anxious-ambiwalent style than in the secure style or the avoidant style during hospitalization. Six weeks later higher level of depression was in the anxious-ambivalent subjects than in the secure. The avoidant style took the middle position and it did not differ with the level of depression from others. The results indicate that the secure or the avoidant style may protect lung cancer subjects from overreacting with depression during hospitalization, but the anxious-ambivalent style may increase the depression level. After the return home the insecure styles may react with stronger depression and the secure style with weaker depression.