The objective of this descriptive study was to evaluate the level of patient`s care complexity in a hospital unit belonging to a school hospital located in São Paulo, Brazil. Data collection was carried out using the Patient Classification System: a proposal to complement the instrument, by Fugulin et al., during thirty consecutive days. The use of this instrument resulted in 1.080 observations obtained from 156 patients' records. The majority of the patients required high level of care dependency; there were differences among the patient`s wards regarding gender and age, type of treatment and patients' level of care complexity. We concluded that there was a need to evaluate the health care providers in the institution, as well as to make adjustments regarding demands for technological and materials resources.6592-6