The purposes of this study were to assess fatigue among elderly citrus farmers and indicating countermeasures to reduce the workload of agricultural work and the work-related stress among elderly citrus farmers. The Fatigue Questionnaire for Farmers developed by the Rural Life Research Institute, Japan was used after a modification by the addition of items related to dietary life. It was found that some of the factors causing fatigue among citrus farmers differed between men and women. There was a clear correlation between agricultural work load and the severity of fatigue. Among these elderly farmers, the qualitative aspect of work stress had much more effect on fatigue than the quantitative aspect. And, the fact that social support impossibility for them deepened their sense of dissatisfaction with work and social life indicated the importance of social support for them. The study suggested that the modified questionnaire was shown to be useful in the assessment of fatigue among agricultural workers; however, it needs to be simplified. Further study using the simplified fatigue questionnaire is needed for further clarification of fatigue and its underlying factors among agricultural workers.