This study aims to identify how differing language experiences impact on the level of oral proficiency attained in the bilingual child’s two languages. Participants were 39 seven- to eight-year-old French-English bilingual children from high SES families attending an international state school in France. Detailed information on the children’s language experiences was gathered through two questionnaires, one completed by the parents and one given orally to each child. Proficiency was assessed in each language using the English and French versions of the standardised Peabody Picture Vocabulary Test, along with criterion-referenced evaluations of oral competence in each language completed by the children’s English and French teachers, and by the researcher, following several individual interviews with each child. Initial analysis of the questionnaires shows that most of the children in the sample fall into one of three family types: nineteen children with one English-speaking and one French-speaking parent who generally follow the OPOL strategy, nine with two French-speaking parents who having lived several years in an English-speaking country, have returned to France and eight with two English-speaking parents who are in France on a short- or long-term basis. Preliminary results suggest that certain factors have a determining role in accounting for the level of oral competence attained in each of the child’s languages but that these factors operate differentially according to family type. The factors identified are quality and quantity of input, discourse strategies within the family and wider community, age and contexts of acquisition, motivation, and child’s rank in the family in relation to siblings. This research is the first part of a Ph.D project which will examine the extent to which degree of bilingualism and language experiences influence bilingual children’s cognitive development and, in particular, metalinguistic awareness in their two languages.