Background: Patient empowerment (PE) may be defined as the opportunity for patients to master issues important to their own health. The aim of this study was to conceptualize PE and how the concept manifests itself for cancer patients attending follow-up, in order to develop a relevant and sensitive questionnaire for this population. Material and methods: A theoretical model of PE was made, based on Zimmerman’s theory of psychological empowerment. Patients who were in follow-up after first line treatment for their cancer (n = 16) were interviewed about their experiences with follow-up. A deductive thematic analysis was conducted to contextualize the theory and find concrete manifestations of empowerment. Data were analyzed to find situations that expressed empowerment or lack of empowerment. We then analyzed what abilities these situations called for and we further analyzed how these abilities fitted Zimmerman’s theory. Results: In all, 16 patients from two different hospitals participated in the interviews. PE in cancer follow-up was conceptualized as: (1) the perception that one had the possibility of mastering treatment and care (e.g. the possibility of ‘saying no’ to treatment and getting in contact with health care when needed); (2) having knowledge and skills regarding, for example treatment, care, plan of treatment and care, normal reactions and late effects, although knowledge and information was not always considered positively; and (3) being able to make the health care system address one’s concerns and needs and, for some patients, also being able to monitor one’s treatment, tests and care. Conclusion: We conceptualized PE based on Zimmerman’s theory and empirical data to contextualize the concept in cancer follow-up. When developing a patient reported outcome measure measuring PE for this group of patients, one needs to be attentive to differences in wishes regarding mastery.