The rasa (emotive aesthetics), one of the major theories of Sanskrit literary criticism, has been expounded and evaluated in many scholarly studies by Indian and other Sanskritists. Some of them maintain that since the rasa deals with the universalized human emotions, it has validity not only for Indian but for other literatures as well. The rasa can be applied to any kind of emotive poetry such as lyric, epic, drama and satire. However, in Thai literature an emotive definition of poetry encompasses a great variety of works. A question is then raised in this paper about whether the rasa can be applied to a Thai poem of didactic nature. Phra Chaisuriya, a versified tale by Sunthon Phu, is selected as an example of study.