Cross-cultural investigation in psychiatry is revealing the need for standardised instruments in diagnosing and assessing depression. Recently, a new instrument was developed to evaluate depressed patients, namely the Montgomery-Asberg Depression Rating Scale (MADRS). The present study introduced the MADRS in Brazil, comparing it to the Hamilton Depression Rating Scale, the Visual Analogue Mood Scale (a self-rating scale), and with the global clinical assessment of independent Brazilian psychiatrists. The results show correlation between MADRS and the three other assessments, indicating that it is a useful and operational instrument to evaluate depressed patients. They also support the application of the MADRS in cross-cultural studies of depression in Brazil and other countries. These results are critically discussed.