OBJECTIVE: Comparison of the association between socioeconomic status (SES) and psychosocial problems in preterm-born and term-born children. DESIGN: Cohort study (Amsterdam Born Children and their Development (ABCD) cohort). METHOD: For 217 preterm-born children (mean gestation 34 weeks), Strengths and Difficulties Questionnaire (SDQ) scores were compared with 4336 term-born children at age 5-6 years. Associations between SDQ scores and SES (maternal education and perceived income adequacy) were examined with multivariate linear regression analysis. RESULTS: Mothers of preterm-born children often had a lower level of education. The mean SDQ total score was significantly higher for preterm-born children (6.1; SD: 4.7) than for term-born children (5.2; SD: 4.1). No significant differences were found between preterm-born and term-born children in the SDQ scores reported by teachers. For preterm-born children, 16.1% of the mothers reported psychosocial problems compared with 10.1% for term-born children. Lower maternal education and lower income adequacy were significantly related to higher SDQ scores. Differences in SDQ score between preterm-born and term-born children were most pronounced in the group with highly educated mothers (Delta0.9; 95%-CI: 0.2-1.5) and high income (Delta0.9; 95%-CI: 0.3-1.6). CONCLUSION: There was no additional effect of preterm birth on psychosocial problems in children with a low level of maternal education or inadequate income. This study corroborates earlier evidence regarding the disadvantageous effects of low SES on psychosocial development.