The purpose of the study was to explore whether gender or ethnicity moderated the links between language skills and teacher ratings of problem behaviour and between language and social skills in 386 English-speaking Hispanic and European American preschool children from low-income families. The "Preschool Language Scale-4" was administered individually to each child participant. Teachers completed the "Child Behavior Checklist/1[superscript 1]/[superscript 2]--5 and the "Social Skills Rating System" for each participant. Results indicated that gender or ethnicity did not moderate the relationships between language skills and problem behaviours. However, the association between language skills and social skills was influenced by gender or ethnicity.