Adopting a multiple-case, multiple-method design, this study investigates mobile technology use in the practices of three experienced second language teachers. The findings, based on an analysis of the teachers' rationales, stated beliefs and classroom actions, show that the teachers tend to prohibit or reluctantly tolerate mobile device usage, while they recognise some of its potential benefits to support their teaching and student learning. They also highlight the incentives and barriers which respectively facilitate and hinder the integration of mobile technology, including factors which are internal (e.g. beliefs) and external (e.g. contextual constraints) to the teachers. Implications for classroom practice and teacher education are drawn.