A classroom lesson about the intake of soft drinks was given to 5th grade elementary school children. An evaluation of the effects was based on the stimulated recall procedure for an analysis of the statements on the worksheets and on a survey of the intake of soft drinks before and after the lesson. The impression of the lesson as stated on the worksheets suggested that the children mainly thought about how they should treat soft drinks in daily life. The findings from the stimulated recall procedure showed that the children willingly participated in the lesson, understood how sweetness is sensed and the amount of sugar intake through their own experience, and thought about how they should treat soft drinks in daily life. The average amount of sugar in soft drinks taken per weekday was 40.1 g/day before the lesson, this figure being significantly reduced to 23.4 g/day after the lesson. However, the amount of sugar intake during school holidays after the lesson was not significantly different from the level before. These results indicate that the lesson was effective for higher grade elementary school children in the sense that their soft drink consumption was improved through their enhanced willingness to learn and their attempts to find a better selection and drinking habit for soft drinks.