Educators and researchers increasingly recognise the impact of language policies on bilingual education. The present study examined the similarities and differences in how the teachers and principals in two different contexts, a Mandarin-English bilingual programme in a Canadian kindergarten and elementary school and a Russian-Hebrew bilingual preschool programme in Israel, understood their language programmes and made curriculum decisions with respect to instructional time for each language. Semi-structured interviews were conducted with five teachers, two principals and a programme manager from the two programmes. Four main themes emerged from the data analysis: (1) experiences in the search for an ideal language programme, (2) challenges arising in realising the bilingual programmes; (3) looking ahead and (4) a flexible and creative approach towards a language separation model. Despite differences in programme ideology and student demographics, findings showed that staff in both contexts faced similar challenges. Educational implications are discussed in relation to the findings.