A method of establishing characteristics of spontaneous and caloric nystagmus frequency as representation of the function of the vestibular-ocular system is proposed. The calculations are represented on a rectangular graphic scheme, ie, the butterfly chart. Butterfly vestibulometry offers two advantages to the examiner: (1) It is an easy method of synoptical recording of caloric nystagmus responses in an objective as well as quantitative manner, and (2) the responses are presented as an easily interpreted figure similar to the audiograms.