Little is known about men's experience of how cancer affects their role as a father. The aim of this study was to gain an understanding of changes in these men's everyday family lives. The study had an interpretative descriptive design, utilizing the concept of transition as a fore structure. Eight men with different types of blood cancer and with children living at home were recruited for the study. Interviews, guided by the main components of the concept of transition, provided qualitative data for analysis. Through the interpretative process, the central theme-change in self-image as a man and as a parent-was generated. This theme consists of the subthemes gaining control, balancing emotions, subjective well-being, being open or not toward the family, and challenges in family life and to family well-being. The time after diagnosis influenced the process of transition. Self-image changes are more obvious shortly after diagnosis. Further study is needed to identify how nurses and other clinicians can assess the family's needs and support the parental role, especially in consideration of the findings of this study.