In patients with acute leukemia we investigated the illness perceptions, lay theories and coping strategies 1 week after diagnosis. Semi-structured in-depth interviews were conducted with 12 patients. The transcribed interviews were analyzed by methods of qualitative research. Dramatic narrations of overwhelming threat in younger patients contrast to rationalization in elderly patients. Feelings of helplessness and efforts of normalization become apparent. Intense descriptions of physical injury due to invasive procedures allow verbalizing the fear of the disease. While coping strategies are complex, the overall importance of trust is recognized. Mortal fears are indirectly indicated. The results have consequences for psycho-oncological training and patient education.