The Strange Case of Dr. Jekyll and Mr. Hyde, by Robert L. Stevenson, first published in 1886, is now a classic of English literature and of the horror genre. Dr. Jekyll, a respected scientist, via a chemical concoction of his can transform himself into Mr. Hyde at will, having a very different, evil personality. Eventually the situation goes out of control. The novel explores de duality of good and evil within the same person. This edition presents the original English text together with the Esperanto translation. Reading parallel texts in Esperanto and in their native language is ideal for Esperanto learners who want to acquire vocabulary, expressions and grammatical constructions. Parallel texts in two languages eliminate the need to resort to external resources, such as dictionaries, and the reader can concentrate on reading, without losing comprehension. Esperanto is an artificial language created by Dr. L.L.Zamenhof, who laid the foundations in the 19th century. It is a very easy language to learn and it is intended to be universal and neutral, which makes it very suitable for international communication. There are Esperanto speakers all over the world, who often travel and meet without language barriers. Esperanto is also increasing its presence on the internet.