Stuffed animal sleepover programs have been conducted by libraries worldwide. This study sought to (1) determine whether the stuffed animal sleepover program increased children's reading and (2) examine the duration of the effect. Forty-two children who attended preschool participated in the study. The results indicated that the number of children who read picture books to stuffed animals increased following the program, but the program's effect decreased within three days. One month later, the children were reminded of the stuffed animal sleepover program. The number of children who read picture books to stuffed animals increased again after the reminder. The results suggest that (1) stuffed animal sleepover programs can positively affect children's reading of picture books, (2) the duration of the program's effect can be short, and (3) reminding children of the program can be an effective strategy to revive and sustain their interest in picture books. These results are discussed in terms of the psychological characteristics of childhood.