This work deals with the management of side effects during oncologic therapy with colorectal cancer patients and also investigates the role of nurses in this setting. Special attention will be given to nursing competences, the sorts of therapy and the nurture relevant side effects regarding treatment. In this aspect, it has turned out that the competences of nurses are divided into several groups. Also within these divisions, the abilities, beeing dealt with in the summary, are very specific. In spite of the progressive improvement of the therapy, an occurrence of side effects and complications are omnipresent. Therefore these are a high relevance for the upscale service. By the elaboration of technical literature and their comparison, these aspects have been worked out, formulated and evaluated to a conclusion. Knowledge, professional skills, and the sense of social sensitivity are included in the field of competence of oncologic care. Know-how about the first manifestations of a side effect and its strategy treatment is one of the daily challenges in the oncology.