Background:The Stockholm region was hard hit by the first wave of COVID-19, although, in contrast to other countries, Sweden introduced less strict protective measures. Furthermore, early studies highlighted the fact that patients with cancer were at increased risk of becoming seriously ill with COVID-19. The aim was to describe perceptions of risk, safeguards, and cancer treatment received among patients with cancer early in the COVID-19 pandemic and to investigate the relationship between these perceptions and undergoing active treatment, self-isolation, and psychological well-being.Methods:This observational cross-sectional study was based on the Swedish sample in a multinational study. Data were collected through an anonymous online questionnaire from a convenience sample of patients with cancer in the Stockholm region of Sweden between the first and second waves of the COVID-19 pandemic.Results:Among participants (N = 76), 9% had been infected by COVID-19 and 62% had been self-isolating for a longer period; 41% of participants stated that they were worried about becoming infected, which was associated with self-isolation and higher levels of anxiety. The majority were confident that family members behaved with caution and followed COVID-19 guidelines, but few had confidence in other people or state authorities. Less than 15% reported that they did not receive medical treatment or supportive care.Conclusion:Despite the small sample size, this study shows that most participants used self-isolation to protect themselves from COVID-19 during this period and that most of the participants perceived that they had received their cancer treatment as planned.