In 30 comatose head injured patients vestibulo-ocular responses were elicited by caloric stimulation. Inter- and intra-observer agreement of these responses was studied. The responses were shown in the form of a film to ten doctors who classified them into four categories: no reaction, tonic reaction, paradoxical nystagmus and nystagmus. The level of the coefficient Kappa (a chance-corrected measure of interobserver agreement) was 0.50; this is within the range of levels for most components of clinical examination reported in the literature.