The Creasey formula [consists] of a fairly rat-tat-tat style—short sentences, lots of padding, emphasis on plot gimmicks, very little in the way of characterization. "Let's Kill Uncle Lionel" is typical of the species…. [It] is a Supt. Folly mystery. Folly is the fat Scotland Yard operative who is only too clearly patterned after John Dickson Carr's Dr. Gideon Fell.

In this book, however, Folly doesn't enter until almost halfway through. There is a great deal of preliminary stuff before the murder occurs. Finally, things get down to a traditional, almost Agatha Christie-like British mystery….

"Let's Kill Uncle Lionel" is not badly written. It is hastily and sloppily written, but at least Creasey has some expertise. (p. 38)

Newgate Callendar, in The New York Times Book Review (© 1976 by the New York Times Company; reprinted by permission), April 11, 1976.