This study evaluated the effectiveness of a synthetic approach to phonics, specifically Jolly Phonics (JP), to determine its contribution to Omani third graders' acquisition of literacy skills. To achieve this, students' performance in these skills was compared with the programme's intended objectives, as set by the Ministry of Education (MOE). Moreover, the study investigated whether there are any differences between boys' and girls' attainment of the target literacy skills. The study sample consisted of 117 Omani male and female third graders in two cycle one schools in Al-Dhahira Governorate in the Sultanate of Oman during the academic year 2019/2020. The study investigated the extent to which the synthetic approach to phonics impacted Omani third graders' literacy skills in terms of: the alphabetic principle (i.e. uppercase (UC) and lowercase (LC) recognition skills, letter-sound correspondence and blending skills); phoneme segmentation skills; accuracy and fluency of reading connected texts; and, spelling skills. It also examined whether gender was a variable. The study employed a quantitative descriptive research design, in which data was collected using four research instruments including the Alphabetic Principle Test, Dynamic Indicators of Basic Literacy Early Skills (DIBLES) Phoneme Segmentation Fluency (PSF) Test, DIBLES Oral Reading Fluency (ORF) Test and a Spelling Test. The validity of instruments was examined by a panel of experts and the reliability was examined by Pearson Correlation Coefficient. Quantitative data gained from the four research instruments were analysed statistically using SPSS. An independent-sample t-test was used to explore any differences with respect to gender. The students' mean scores in the four tests were calculated and then compared to the minimum required level for each skill using the one-sample t-test to present a general estimated effect ofJP on third graders' literacy skills. Additionally, descriptive statistics were used to analyse the specific impact of this programme on each skill separately. The findings revealed that the Omani third graders in the study sample on average have achieved JP's objectives and performed at or above the required grade level in phoneme segmentation skills, letter-sound correspondence and UC and LC recognition. However, on average, they have not achieved the JP's objectives and performed poorly against the grade level expectations for accuracy and fluency of reading connected texts, spelling skills and blending skills. Moreover, the findings revealed weaknesses when segmenting whole words correctly, as well as weaknesses identifying most of the letter-sound correspondences, except for consonants, which most students were able to identify. With respect to gender, there were no statistically significant differences between males and females in the literacy skills tested. Different contextual factors contributed to these findings. Some relate to the programme's implementation; i.e. the number of JP lessons, number of phonics, phonemic awareness, reading and spelling practice activities provided in the JP students' phonics handbook, the unavailability of graded readers within the programme; and teacher related factors including current practices regarding the plan set by the Ministry, teachers' levels of phonemic awareness, the adequacy of the JP training they received. The study concluded with a set of recommendations for the MOE, English regional supervisors, English senior teachers and English teachers, in order to develop the delivery of synthetic phonics teaching as a literacy-enhancing approach, namely JP, in the Omani context. Finally, suggestions for future research were proposed.