[4] The author profile in the first edition describes Robert Foster as the then-"Tengwar Consultant" to the Tolkien Society of America.

[9] A revised edition (ISBN 0-345-44976-2) was published in 2001, in time for Peter Jackson's The Lord of the Rings film trilogy.

[3] A new hardback edition illustrated by Ted Nasmith, including standard and slipcased versions, was released in September 2022.

[12] Lester del Rey praised the 1971 version for covering "literally everything you wanted to know about Middle Earth and were unable to discover before.

[3] Dissenting, Adam Roberts, writing in The Times in 2022, calls the revised edition disappointing and "woefully outdated" in the face of the wealth of information on Tolkien now available on the Internet.

[15] A German edition, Das Große Mittelerde-Lexikon, revised and translated by Helmut W. Pesch, was published in 2002.