This study explored receptive vocabulary size and early literacy skills (namely: letter naming, knowledge of phoneme-grapheme correspondences and early writing) in emergent bilingual Northern Sotho-English children. Two groups of Grade 1 learners were tested in both English and in Northern Sotho. Group 1 (N = 49) received their formal schooling in English, whilst group 2 (N = 50) received their formal schooling in Northern Sotho. Receptive vocabulary was tested using the Peabody Picture Vocabulary Test. Letter knowledge was assessed by asking learners to name letter cards, whilst knowledge of phoneme-grapheme correspondences was tested by asking children to match letter cards with spoken sounds. Early writing was assessed by asking children to write their names. Statistical analyses indicated that both English and Northern Sotho receptive vocabulary knowledge had a significant effect on early literacy skills, whilst no main effect was found for the language of instruction. Group 1 performed significantly better than Group 2 in English receptive vocabulary, in knowledge of phoneme-grapheme correspondences and in early writing, but no group differences were found for Northern Sotho receptive vocabulary or for letter knowledge. English receptive vocabulary significantly predicted the outcome of all of the early literacy skills, whilst Northern Sotho receptive vocabulary significantly predicted phoneme-grapheme correspondences and early writing.