Studies have shown that phonics instruction improves reading skills, with noticeable word recognition and pronunciation results. Despite the intensive use of this method in English countries, phonics has not been introduced or is minimally taught in Indonesian primary schools' English reading classes, where the teaching is mainly focused on text comprehension. This study aims to trial a systematic instruction in synthetic phonics to see whether the trial helps students improve their pronunciation and comprehension skills. Thirty-third graders from an Indonesian bilingual school and their English teachers were selected to participate in a sixmonth trial of synthetic phonics instruction, extended to a storybook reading programme. Pre-and post-experimental design was employed to measure the trial's effectiveness. Teachers' interviews and students' questionnaires were used to understanding their perspectives on the trial's benefits and feasibility for further implementation. The findings revealed that the trial accelerated students' decoding skills and improved word pronunciation and text comprehension. Another test of a paired sample t-test also highlighted the trial's significance (sig .01). Students also shared their experiences of improved vocabulary, confidence and enjoyment. The teachers agreed on the benefits of the trial. Still, they were unsure how to deliver the instruction in regular classroom sessions since it required long and vigorous direct teaching. Findings from this trial were not generalizable to EFL reading classes in Indonesian primary schools as it was tried out in a bilingual school where phonics was minimally introduced. However, the findings generally indicated the program's feasibility which can be re-tested.