Background: Analysis of the workload can find out the optimal number of human resources in the required nutrition departmen, both from the type and amount. This is because the excess of human resources can have an impact on the use of unproductive work time and the shortage of human resource has an impact on excessive workload Method: mixed methods research that is Sequential Explanatory quantitative method with an observation approach using work sampling where the respondent's activities are observed and researched every 10 minutes for 7 working days, then the use of productive time obtained is used to calculate power needs by using the calculation of workforce needs with the formula Workload Indicator of Staffing Need (WISN) and qualitative methods are carried out using in-depth interviews with Human Resources manager, nutrition manager and staff employees Result and discussion: This study illustrates the workload of nutritionists at 53.7%, at processing or cooking staff at 50.4% and presenter at 44%. the amount of work time available is 115,920 minutes for one year in the nutritional installation of Muhammadiyah Hospital PKU Bantul. The standard amount of allowance for nutritionists is 0.322, processors or cooks is 0.322 and presenter is 0.322 for nutrition in PKU Muhammadiyah Hospital Bantul. Conclusions: Based on the calculation of labor needs using WISN, it was found that the number of workers in the nutrition department was 24 people. From these calculations it can be concluded that the number of workers needed to carry out the workload needs to add 5 people in the nutritionist division and there are excess employees in the food services as much as 1 person and for the cooking staff is appropriate that is as many as 5 people.