Existential guilt is a deep and multidimensional concept that is correlated with concepts, such as in/authenticity, existential anxiety, decisiveness, and personal and social responsibility. The aim of the present study is to investigate the experience of existential guilt among cancer patients.

The present research was conducted with a qualitative method with a content analysis design. A purposeful sampling method was used to select the participants and the sampling procedure went on until we reached data saturation. Data were obtained using semi-structured interviews with the participants.

From a total of 18 interviews, 94 codes related to existential guilt were obtained. After the analysis, three main concepts were extracted: (1) incompleteness, (2) passivity, and (3) feelings of harm to self and others. Each of these had a number of subcategories.

The participants of the present research were found to experience existential guilt in different ways. The research showed that it is necessary to find the sources of existential guilt in order that effective therapeutic attention can be given cancer patients.