Purpose <p>The COVID-19 pandemic and associated measures negatively impacted health outcomes of patients with severe diseases. This study investigated the short- and intermediate-term impact of the pandemic on cancer survival.</p> Methods <p>This study was based on cancer registry data of the Swiss cantons of Zurich and Zug from 2018 to 2021. Observed and relative one- and three-year survival were calculated based on lifetables for the population covered by the registry. Multivariable Royston Parmar survival regression models were fitted to compare survival before (2018/2019) and during the pandemic (2020, 2021). For patients diagnosed during the pandemic, a counterfactual analysis was conducted. Analyses were performed for overall cancer and the five most common cancer types.</p> Results <p>Overall, 32 826 cancer cases were included. One- and three-year survival for all-cancer continuously increased from 2018 to 2021. Compared to pre-pandemic, the hazard of death was lower for all-cancer during the pandemic (2020: Hazard Ratio 0.93 [95% Confidence Interval 0.89, 0.96]; 2021: 0.91 [0.87, 0.94]) and for skin melanoma in 2021 (0.79 [0.62, 0.98]), but higher for colorectal cancer during the pandemic (2020: 1.17 [1.03, 1.32]; 2021: 1.24 [1.09, 1.40]). Observed one-year survival for all-cancer, female breast, and prostate cancer was higher in 2021 than predicted. In 2020, observed one-year survival of colorectal cancer and three-year survival of female breast cancer were lower than predicted.</p> Conclusion <p>The COVID-19 pandemic appears to have had only a minimal impact on the overall increasing cancer survival trend in Switzerland, reflecting the robustness and resilience of the healthcare system.</p>