ABSTRACT Objective: To estimate the cost of nursing care required and available through the use of the Nursing Activities Score. Method: Quantitative study, direct costing of nursing care required and available in the Intensive Care Units. Data collection included variables of the patients, nursing professionals and nursing workload measured by the Nursing Activities Score. The cost of nursing care was estimated by multiplying the cost of each hour with the total number of hours of care per category. Results: The negative difference of R$ 94,791.5 between the cost of available and required nursing care indicated an increase of 3.2 nurses and 7.0 nursing technicians. Conclusion: The cost of nursing care required identified through the application of the Nursing Activities Score, which is higher than the cost of available care, indicates the need to adjust the number of professionals to meet patients' demands.