This research is aimed to find out the comparison of speaking ability between Islamic boarding school and non-Islamic boarding school alumni. The samples of this research were 20 students from English Education Department of UIN Ar-Raniry who have completed Advanced Language Skills (ALS) class. The quantitative method was used to reveal students’ speaking ability. In this research, test and semi-structured interviews were used to collect data. The researcher analyzed the data using a speaking rubric with total score of each five aspects of speaking; pronunciation, grammar, vocabulary, fluency and comprehension. The result found that alumni of Islamic boarding school students’ overall score is higher than non-Islamic boarding school with total 76.4 : 68.4. In other words, the higher score shows that students from boarding school is more advanced in speaking ability. The reason that distinguishes speaaking ability from Islamic boarding school and non-Islamic boarding school is because of the process of implementing learning.