In recent years, with the rapid development of mobile devices, mobile learning (m-learning) has becoming another popular topic. There is a strong need for both researchers and educators to be aware of adult learners' attitudes toward English mobile learning, yet relevant studies on mobile learning to promote English learning for adult learners are scarce. The purpose of this study was to describe the development of an English Mobile Learning attitude scale for adult learners in higher education. A preliminary version of a scale to measure attitudes toward English mobile learning was developed and piloted on 190 adult learners who were attending the continuing education situations in Southern Taiwan. Initial item selection produced a pilot scale consisting of 36 Likert items. Subsequently, an expert review panel, item analysis, and factor analysis revealed four structurally independent attitude constructs and justified retention of 21 of the original items. The full instrument was found to have both a high internal reliability coefficient (0.93) and significant construct validity (p < 0.001).