With the many varied ways that have been used to teach Reiki, there have emerged many points of controversy between different groups, teachers and practitioners. Controversies often exist on topics such as the nature of the Reiki energy itself, fees charged for courses and treatments, training methods, secrecy of symbols and attunement methods, to name but a few.

Various claims are made as to the 'legitimacy' or 'authenticity' of various schools of practice - with the schools making those claims also engaging in criticisms of the other schools who they see as illegitimate or otherwise inauthentic or immoral in their spiritual conduct. Political fighting is quite strong between many schools; so for example a practitioner of one teacher may often not be welcome to practice Reiki with another teacher's Reiki group. Teachers from other schools are often not welcomed in other teacher's classes. A Reiki school will often discourage the participation of outside students and teachers, particularly when there are claims of an individual school's practices being the only correct practice. This occurs amongst both traditional and non-traditional schools. Often and as a more mild form of enforcing adherence, the unorthodox person is required to be retrained in their levels before being accepted into the fold.