A number of studies have shown that teaching science to the English Language Learners (ELLs) remains a challenge faced by many science teachers around the world. The purposes of this study were to explore and document science teachers' experiences in teaching Science to ELLs at a National Plus School (NPS) in Indonesia. The NPS is known to be a bilingual school that offers both national and international curricula in tandem. Science is one of the subjects that are taught both in Indonesian and in English. The school serves for mostly Indonesian students whose first language is not English. An instrumental and multiple case study design was employed to explore the experiences of the science teachers in the school. Four science teachers were recruited using convenience and purposeful sampling strategies. The primary data were collected through semi-structured interviews. The interview conversations were audio-recorded. The researcher transcribed the recordings verbatim. He employed constant comparative method and implemented open, axial, and selective coding strategies. In analyzing the data, the researcher first performed the within-case analyses where each case was analyzed one at a time and the reports for each case were generated separately. Next, the researcher performed the cross-case analyses where the cases were compared and contrasted with one another and a report in which the differences and similarities among the cases were reported. Five themes emerged from the data analyses: (1) Teachers perform double duty as they are teaching science to ELLs, (2) A non-lecture learning environment is well-suited for science teachers, (3) Computational science vs narrative science, (4) Language acquisition is important but not a sole determining factor in learning science, and (5) ELLs in upper grades are susceptible to not learning science in English.
