The Book on Mediums, or The Mediums' Book (Le Livre des Médiums in Frech) is a book by Allan Kardec published in 1861, one of the five Fundamental Works of Spiritism -- the religious philosophy Kardec had been publishing.

It is intended to be handbook for would-be mediums, containing doctrine and practices that one must master in order to become a medium.

The Book on Mediums set the bases and the terminology that guided Parapsychology and Paranormality for quite sometime. In its pages one will find a no-nonsense classification of paranormal phenomena, with a special focus on those capable of communicating messages, and thorough descriptions of the mechanisms that -- according to

The book's signature is it focus on theory instead of practice: not a single line of ritual is given (Spiritists believe all rituals are deviations), unless you consider recommendations for prayer (without giving formulae) as "ritual".

In its first part, there is an overall introduction to the beliefs of Spiritism. For this reason, and considering the overall lighter reading, this book can be recommended to be read before even The Spirits Book.