The CA retrievable information on the thio-, seleno-, and telluroketene substructures (1967 through mid-1991), together with pre-1967 and additional post-1967 information retrieved from reviews and handbooks of organic chemistry, is listed in this paper. This annotated data sheet mentions 335 compounds (systematized in 14 Tables) and 363 refrences including 19 reviews (Ref. 16,33,45,46,75–77,103, 107, 156, 158, 161, 165, 166, 179, 224–226, 363) and thus attempts to present a complete list of title compounds, including radicals and ions as well as chemical entities only appearing as hypothetical intermediates. Polymers, dimers, and compound mixtures are not included.