The aim of this study was to assess the impact of coronaphobia on treatment and follow-up compliance in cancer patients. The records of 230 cancer patients were reviewed. Coronaphobia was assessed via the validated COVID-19 Phobia Scale (C19P-S). A total of 64% of the patients had a high coronaphobia score. Among them, 59% were noncompliant. In multivariate logistic regression analysis, low educational status, treatment type, following COVID-19 news, having knowledge about COVID-19 transmission and higher C19P-S score were associated with noncompliance (p = 0.006, p < 0.001, p = 0.002, p = 0.002 and p = 0.001, respectively). Multivariate analysis revealed that having knowledge about COVID-19 transmission was related to a higher C19P-S score (p = 0.001). The cancer patients studied had significant coronaphobia. Moreover, greater coronaphobia was significantly associated with noncompliance with follow-up and treatment.