Abstract Background Despite the numerous tools built ad hoc to investigate the effects of the CoViD-19 pandemic on people, to date there are no known questionnaires that investigate the emotional experiences of cancer patients. This work aims to start a process of construction and validation of a tool that captures these aspects (Pandemic Emotions Questionnaire in Cancer Patients—PEQ-CP). Method A mixed method approach was used through three phases, each on a different sample: Phase 1: creation of items and checking of internal validity, through unstructured interviews and verification of the validity of content by "peers" and "experts"; Phase 2: exploration of the factorial structure of the scale through an exploratory factor analysis (EFA); Phase 3: confirmation of the factorial structure of the scale through a confirmatory factor analysis (CFA). Results Phase 1 revealed 26 items that can be grouped into 4 theoretical dimensions. "Peers" and "experts" rated all items as understandable and relevant except one, which was reformulated. The EFA in the Phase 2 revealed a factorial structure with 14 items and three dimensions (Emotional Understanding, Communication of Emotions, Feelings the same as others), confirmed by the CFA in Phase 3. Conclusion Although further validation steps are required, the PEQ-CP showed good psychometric properties.