The closest parallel in Western philosophy to the practice of Reiki is faith healing or the laying on of hands in a spiritual sense. The Reiki practitioners believe the the life force is channeled through the bodies to the hands where it can be sent into the body of the client or patient. This is done through two processes, first attunement to receive the flow of the life force by the Reiki master, then the positioning of the hands and sometimes other parts of the body such as the eyes or the breath to channel this flow to the patient.

Those who wish to become Reiki therapists under traditional Usui Reiki must learn from a Reiki master in an unbroken line from the original Grand Master. According to traditionalists, Reiki cannot be learned; it must be experienced.

All training courses in the United States originate from the Grand Master, Mrs. Hawayo Takata who claimed to be a student of one of the students trained by Usui. Although some of her claims are not able to be confirmed, such as the statement that no Reiki Grand Masters in Japan survived World War II, she trained at least 21 masters in the years between 1970 and 1980 in the traditional Usui method.

Even amongst traditionalists, the Reiki course will differ somewhat, as some Masters do not teach students to pass on the method to others, only to use it in healing. Others insist to be recognized as a Master, the student must be able to teach the techniques.

The traditional Reiki course consists of three levels, Levels I and II can usually be mastered in one 6-8 hour session for each component. Level I for example would include information about the history of Reiki, a ceremonial process called attunement, which is a structured formalized series of movements, chants, hand positions and touching, provided by the Master to each of the students. There are four attunements during the Level I course. Also included in Level I is practice of the hand positions required for Self-Attunement and later, practice of the same hand positions as they are used on another person. The Level I Reiki is completed with the first session.

Some people elect to stop at Level I, but others choose to continue to Level II Reiki. The second course is taught in two 3 hours sessions, sometimes separated by over night, but at least 2 hours must elapse between the first and second sessions in order to provide learning and memorization of the names and descriptions of the Reiki symbols. These symbols are important to the practitioners and must be called and drawn correctly so that they may be visualized correctly when applying attunement or therapy to oneself or to others. Two more attunements are given during the Level II course.

At Level III, a divergence of opinion among Masters occurs. Some treat Level III as a continuation of Level II with additional emphasis on both the symbols and channeling the life energy, as well as practicing distance healing; while others believe that to complete Level III, sometimes called Reiki Master Level, the student must successfully teach others the techniques of Reiki.