The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is estimated to have claimed more than 6 million lives globally since it started in 2019. Germany was exposed to two waves of coronavirus disease 2019 in 2020, one starting in April and the other in October. To ensure sufficient capacity for coronavirus disease 2019 patients in intensive care units, elective medical procedures were postponed. The fraction of major abdominal cancer resections affected by these measures remains unknown, and the most affected patient cohort has yet to be identified. This is a register-based, retrospective, nationwide cohort study of anonymized 'diagnosis-related group' billing data provided by the Federal Statistical Office in Germany. Cases were identified using diagnostic and procedural codes for major cancer resections. Population-adjusted cancer resection rates as the primary endpoint were compared at baseline (2012-2019) to those in 2020. A change in resection rates for all analyzed entities (esophageal, gastric, liver, pancreatic, colon, rectum, and lung cancer) was observed from baseline to 2020. Total monthly oncological resections dropped by 7.4% (8.7% normalized to the annual German population, P =0.011). Changes ranged from +3.7% for pancreatic resections ( P =0.277) to -19.4% for rectal resections ( P <0.001). Reductions were higher during lockdown periods. During the first lockdown period (April-June), the overall drop was 14.3% (8.58 per 100 000 vs. 7.35 per 100 000, P <0.001). There was no catch-up effect during the summer months except for pancreatic cancer resections. In the second lockdown period, there was an overall drop of 17.3%. In subgroup analyses, the elderly were most affected by the reduction in resection rates. There was a significant negative correlation between regional SARS-CoV-2 incidences and resections rates. This correlation was strongest for rectal cancer resections (Spearman's r : -0.425, P <0.001). The pandemic lockdowns had a major impact on the oncological surgical caseload in Germany in 2020. The elderly were most affected by the reduction. There was a clear correlation between SARS-CoV-2 incidences regionally and the reduction of surgical resection rates. In future pandemic circumstances, oncological surgery has to be prioritized with an extra focus on the most vulnerable patients.