First published in 1976 and by Fontana in 1977. This edition was the eighth impression, printed 1982.
Like Curtain, Christie wrote this novel more than thirty years before its publication. She wrote it as a backup should she need some extra money, but ended up leaving it until her health stopped her from writing. She ordered it to be published, but died before it was actually printed. There are some chronological errors where Christie didn't have enough time to properly proof read. Some characters included in Sleeping Murder had actually died in previous stories (though of course, Christie wrote them after Sleeping Murder!)