The purpose of the study was to characterize the relationships between behavior problems, academic achievement, and loneliness of students in the upper and lower thirds of a social skills classification. Participants were 733 students (359 boys and 374 girls) ages 9 to 14 years, 642 without learning disabilities (LDs) and 91 with LDs. Their homeroom teacher rated their social skills, and accordingly the upper and lower thirds of social skills scores were determined. Results showed differences in behavior problems between the low and high social skills groups. Boys displayed higher rates of behavior problems. Students with LDs achieved lower scores than their peers in academic achievements and higher scores in loneliness. The final model of the binary stepwise logistic regression showed that loneliness, behavior problems, and academic achievements were related to social skills, explaining 60% of the pseudo-variance (Cox & Snell R[superscript 2] = 0.60). The findings help target individual variables that can promote school adjustment.