During the last decades, autopsy rates have dramatically decreased in many countries. The Cancer Registry Zurich, which exists since 1980, provides the opportunity to address to what extent the number of autopsies in cancer patients has changed over a longer period of time and how often autopsies provide a diagnosis of clinically undetected cancer. Data from the Cancer Registry Zurich consisting of 102,434 cancer cases among 89,933 deceased patients between 1980 and 2010 were analyzed by means of descriptive statistics. The autopsy rate declined from 60 % in 1980 to 7 % in 2010. The total number of autopsies performed decreased from 1179 in 1986 to 220 in 2010. Furthermore, there was also a decline in the rate of newly detected tumours based on autopsy information. In 1980, the rate of newly detected tumours through autopsy was 42 % compared with 2010, when the rate had declined to 17 %. A consequence of the reduced autopsy rate is the reduction of incidental findings at autopsy in cancer registration. However, this reduction has not negatively affected the total incidence of cancer. It seems that the state-of-the-art diagnostic tools used for tumour detection are sufficiently reliable, allowing the scientific community to trust the quality of data provided by cancer registries in spite of decreasing autopsy rates.