This investigation consisted on a prospective cross-sectional study that aimed to describe the nursing team knowledge on behavioral assessment of pain. The study was conducted in a private hospital in the city of Sao Paulo, Brazil in November 2011, with nursing professionals from a general adult intensive care unit. They answered a questionnaire that contained sociodemographic data and questions related to knowledge about a behavioral assessment of pain. Descriptive data analysis was carried out and the average positive score was compared among categories using the Mann-Whitney test. Out of the 113 participants, over 70% have demonstrated knowledge of the main aspects of this assessment and there was no statistical significant difference among the professional categories. It was concluded that the knowledge of the professionals was satisfactory, but it can be improved.