We focused on current commercially available super-concentrated liquid laundry detergent and analyzed high school home economics textbooks. We analyzed the descriptions of such things as washing conditions, synthetic detergents, bleach, and softening agents. As a result, we found that the description of super-concentrated liquid laundry detergent was insufficient. Ten of the 17 high school home economics textbooks that we analyzed described changes in detergent concentration, bath water ratio, number of times rinsed, clothing smell, etc. related to lifestyle changes in recent years. Only four of the textbooks, however, contained descriptions of super-concentrated liquid laundry detergent. It was revealed that home economics textbooks do not necessarily reflect actual conditions. Based on these analyses, we suggested that a problem exists in the teaching of high school home economics when it comes to washing clothes.