The overall aim of the RAFAELA system is that the personnel resources should be in balance with the patients' caring needs, i.e. when the nursing intensity per nurse is on the optimal level of the unit. The RAFAELA system consists of three parts: the OPCq (Oulu Patient Classification Qualisan) instrument for measuring the nursing intensity, registration of the daily nursing resources and the PAONCIL (Professional Assessment of Optimal Nursing Care Intensity Level) method. The aim of this paper is (1) to describe the structure of benchmarking with the RAFAELA system and (2) to present comparisons of optimal nursing intensity levels in Finnish hospitals by using data from RAFAELA benchmarking reports in 2001. Totally 86 wards from 14 different hospitals in Finland took part in the study, the optimal nursing intensity had been decided for 53 wards. Data was analyzed using descriptive statistics. The average workload was on adult wards 25.2 NCI points per nurse. The optimal NCI was exceeded during 48% of the days and under during 22% of the days. An imbalance between nursing intensity and personnel resources clearly affects the care quality and the results. Benchmarking with the RAFAELA system provides nurse managers with many opportunities in their decision processes in human resource management.