Adults who utilize trade books when working with children should be aware of the differences in gender portrayal of adults in children's science trade books. This paper describes the results and implications of a gender representation study of the visuals in children's science trade books identified as outstanding by the National Science Teachers Association in 1976 and 1993. The humans shown in the visuals in these books were evaluated not only for the frequency of male and female representations but also for the type of portrayal. The evaluation of each human found in a visual included the (a) content category (biological or physical), (b) physical activity, (c) location, (d) occupation, (e) tool use, and (f) personal interactions among the humans. Significant differences in the frequency and type of portrayal of males and females were found between content categories within a single year and between years. Some of the changes in gender portrayal observed between the two years mirror changes in gender role found in society during the past 17 years. The significant differences which reflect society were seen in three categories-age, activity level, and occupations. Age and occupation differences are described in this paper. (Author/JRH)