The COVID‐19 pandemic has caused disruptions to national health systems and impacted health outcomes worldwide. However, the extent to which surveillance systems, such as population‐based cancer registration, have been affected was not reported. Here we sought to evaluate the effect of the pandemic on registry operations across different areas and development levels worldwide. We investigated the impact of COVID‐19 on three main areas of cancer registry operations: staffing, financing and data collection. An online survey was administered to 750 member registries of the International Association for Cancer Registries. Among 212 responding registries from 90 countries, 65.6% reported a disruption in operations, ranging between 45% in south‐eastern Asia and 87% in the Latin America and Caribbean. Active data collection was disrupted more than case notifications or hybrid methods. In countries categorized with low Human Development Index (HDI), a greater number of registries reported a negative impact (81.3%) than in very high HDI countries (57.8%). This contrast was highest in term of impact on financing: 9/16 (56%) registries in low HDI countries reported a current or an expected decline in funding, compared to 7/108 (7%) in very high HDI countries. With many cancer registries worldwide reporting disruption to their operations during the early COVID‐19 pandemic, urgent actions are needed to ensure their continuity. Governmental commitment to support future registry operations as an asset to disease control, alongside a move toward electronic reporting systems will help to ensure the sustainability of cancer surveillance worldwide. What's new? The COVID‐19 pandemic has caused disruptions to health systems worldwide. Has it also affected surveillance systems, such as population‐based cancer registries? In this study, the authors found that two‐thirds of analyzed cancer registries reported disruption in staffing, finances, and/or data collection. In countries with a low Human Development Index (HDI), a greater number of registries reported a negative impact (81.3%) than in very high HDI countries (57.8%). These results emphasize the need for actionable, strategic plans to ensure the continuity of registry operations globally.