Home health care is moving into a set of new realities. An era of competition and cost containment has arrived. Before nurses are able to contain costs or describe the relationship between nursing activities, cost must be accurately measured based on the nurse's workload. Nurses in home health care usually desire to measure expenses for one of three reasons : reimbursement, management, or research. The purpose of the study was to investigate the work input by Registered Nurse in each of the home health care activities by relative value units and identify the factors affecting the nurses' total work input in health care services. To measure the work input by nurses, work was defined by four dimensions: time, physical effort, mental effort, and stress. This study used a descriptive-correlational design. Data collection consisted of two phases. In phase I, data on home health activities performed by nurses were collected. In phase II, data on nurses' time, physical effort, mental effort, and stress in each of home health care activities discovered phase I were collected. In this method, the respondent was asked to rate a service in relation to a reference service using a ratio scale. The sample included 39 home health care nurses. The results of the study indicated that home health care activities performed by the nurses were in 10 categories and 69 items. Measuring the relative work inputs in each of home health care activities, and foley catheterization was selected as the reference to service. In terms of time and physical effort dimensions, full bath service was rated as the most strenuous among 69 activities by the respondents, and intramuscular injection was rated as least. It was found that emergency treatment required the highest mental effort and the highest stress, while blood sugar tests required the lowest mental effort. Approximately 91.3% of the variance in total work input was accounted for by the linear combination of time, physical effort, mental effort judgement, and stress. Examining the regression coefficients of those variables, physical effort, time, and stress were found as the predictors which were significantly associated with the total work of nurses in home health care. Professional nursing's next step in the conundrum of economic volatility is to develop a tool to reflect the interaction of functional deficiency and direct professional nursing care. And this will be a more accurate predictor of nursing resource use and ultimately a great forcaeter cost.