The English Expert program (EEP) is one of the long-term in-service training programs at the Specialized Center for Professional Training of Teachers (SCPTT). The current study aims to investigate whether the programs' objectives of the methodological part and the language proficiency part have been attained or not from the participants' perspective. Besides, it investigates the effects of different variables such as gender, teaching experience, cohort, and teaching level on the accomplishment of the program's objectives. An explanatory sequential mixed methods design was followed in this study. The data were collected through a questionnaire for the participants, and a content analysis of the participants' reflection reports. The study includes the participants of the first and the second cohorts (around 82 participants). A sample of 60 participants responded to the questionnaire, and a sample of six participants was purposefully selected for the qualitative data (a total of 36 reflection reports). The findings of the study reveal a high achievement of the objectives of both parts. Regarding the quantitative data, the objectives of the methodological part (items 1 to 45) of the EEP were highly achieved (M= 4.42, SD= 0.45). Besides, the objectives of the language proficiency part (items 46 to 85) of the EEP were highly achieved too (M= 4.42, SD= 0.46). The qualitative data analysis supports the results of the quantitative data. Variable such as gender, teaching experience, cohort, and teaching level had no statistically significant differences on the achievement of the EEP's objectives. The participants' attitude toward the EEP is very positive. However, a revision of the content in some areas is suggested for a better future improvement. Suggestions and recommendations are made for improving the EEP.