Background <p>Although a sample of research provided a context associated with negative impact for negative body image, the longitudinal association between negative body image, internalizing problems, and social withdrawal remains unclear.</p> Objective <p>This study examined the longitudinal relationships between negative body image, internalizing problems, and social withdrawal among primary school students.</p> Method <p>The study used the Random Intercept Cross-Lagged Panel Model (RI-CLPM) with three waves of longitudinal data. Participants included 821 children aged 9 to 13 years (<i>M</i> = 10.48, <i>SD</i> = 1.08) who attended primary schools in China. Children completed a paper questionnaire assessing negative body image, indices of internalizing problems (i.e., anxiety, depression, stress), and social withdrawal.</p> Results <p>The results at the between-person level showed that negative body image, internalizing problems, and social withdrawal were positively correlated. Among the results, there was a unidirectional link between negative body image, internalizing problems, and social withdrawal at the within-person level, with internalizing problems playing a mediating role in the association between the negative body image and social withdrawal.</p> Conclusion <p>Primary school students who have a bad body image may eventually experience internalizing problems that trigger them to withdraw from social activities.</p>