This study investigated links between motivations for social withdrawal, time spent alone, and indices of internalizing difficulties. Participants were 169 (n = 96 girls) children and early adolescents aged 8-14 years (M[subscript age] = 10.82, SD = 1.78). Children completed self-report measures of motivations for social withdrawal (shyness, unsociability), time spent alone, and indices of internalizing difficulties (social anxiety, depression, loneliness), whereas parents provided a broader rating of children's internalizing symptoms. Among the results, at higher levels of shyness, time spent alone was positively related to social anxiety, but this association was attenuated at lower levels of shyness. Higher levels of unsociability weakened the positive association between time spent alone and loneliness. Time alone was more strongly related to depression for early adolescents. These findings highlight the differential implications of solitude for shy children and early adolescents, who might experience more discomfort and anxiety compared to their more unsociable counterparts.