In the article a new method is presented for allocation of staff resources, 'Professional Assessment of Optimal Nursing Care Intensity Level' (PAONCIL). This method is presented as an alternative to classical time study, which has traditionally been considered to belong to systems for patient classification. By means of this method the optimal nursing care intensity level for individual wards can be established. The study comprised 8 wards, and the nurses working in these wards provided a total of 8,458 professional assessments of optimal nursing care intensity levels. The material was analysed by means of simple linear regression analysis. The nursing care intensity scores per nurse in a single ward were used as independent variables and the average PAONCIL score for the same calendar day was used as a dependent variable. The average determination coefficient for different wards were 0.37; the PAONCIL instrument thus explained 37% of the nursing care intensity/nurse variation. This corresponded to a linear correlation of 0.60. In five out of six wards for adults the optimal nursing care intensity/nurse scores were close to each other, ranging from 3.0 to 3.6. The advantage of the PAONCIL method is that it can be easily implemented in a ward, can be used time and again, is advantageous and is based on quality aspects. The PAONCIL method has been developed on the basis of a caring science perspective and can be seen as an administrative method for the nurse manager, with whose help 'good care' can become possible.