The present dataset is referred to a study aimed to investigate socioeconomic status (SES), verbal skills and language background as concurrent predictors of socio-emotional and behavioural skills in heritage bilinguals and monolingual peers attending preschool. Parents of 1810 preschoolers filled in the Four Factor Index of SES and the Strengths and Difficulties Questionnaire (SDQ). Teachers compiled a questionnaire on children’s linguistic skills as well as emotional and behavioural profiles. A subsample of children was administered an expressive vocabulary task