Technology and validation methods for producing biodiesel have been updated and have kept advancing. Creative raw materials used in producing environmentally friendly biodiesels have also attracted interest from scientists. Thus, learning and teaching methods on biodiesel production at the high school level need to be up to date. However, there are expensive instruments required in performing experiments. This limitation reduces students' chances in integrating their chemical knowledge with the current situation. This study aims to develop a STEAM activity on biodiesel production by using waste vegetable cooking oil (WVCO) for high school students in Thailand. A simple and inexpensive experiment is described. The produced biodiesel was qualitatively analyzed by using thin-layer chromatography (TLC) and compared with a standard biodiesel. The basic science process skills (BSPS) and the learning achievement on biodiesel production of 60 students from a high school in Nakhon Phanom province were assessed. The findings of this study revealed that there were benefits to including art in this STEAM activity, including encouraging effectiveness in communicating scientific ideas of the students with the lowest BSPS score and encouraging creative thinking of the students while practicing their science laboratory skills. The satisfaction of the students toward the STEAM activity was at a good level. Guidance for teachers to further implement the STEAM activity in schools is provided.