This study is aimed at ensuring the validity of the Practical English Certification Test (PECT) of the Chung-nam Office of Education (COE) in Korea. Motivated by the demand for a developing localized English test to empower English learning in public education, the COE conducted the PECT for 38,544 students of elementary, middle and high schools in Chung-nam Province. The present study was designed to conduct the content and construct the validity of the PECT. Content validity was investigated by a critical review of researchers and educators in English education and proposed that the PECT is fulfilled with clarity in wording, relevance of items, formatting of items and clarity of the instructions. Likewise, in order to ensure the construct validity of the PECT, the present study sampled 148 students (i.e., 52 elementary, 44 middle and 57 high school students) from a total of 38,544 PECT takers and encouraged them to take the standardized English tests (i.e., PELT for elementary level and TOEIC® for secondary level). The findings reported that the PECT is substitutable for the standardized tests, PELT and TOEIC®. In short, the study suggests that conducting the localized English test, the PECT, seems worth trying in order to measure learners' achievement accomplished by English learning in public education.