For technology integration to achieve intended instructional objectives, professional development is of paramount importance for in-service instructors. Technology enhanced reflection providing multimodality and evidence-based data has the potential of helping instructors achieve technology integration in their teaching. Thus, this study addressed the lack of professional development programs for in-service English language instructors aiming at technology integration through evidence-based multimodal reflective practices. By following the developmental research methodology, an instrumental case study was conducted using mixed-methods design including both qualitative and quantitative data. The professional training was carried out with eight English language instructors at tertiary level who aimed to integrate technology into their English classes by being involved in evidence-based multimodal reflective practice. In this study, there were five different data sources (instructors' opinions, recorded lessons, video annotations, face-to-face interaction notes and pages in the learning management system) and seven data collection tools (interviews, tutor reflection template, self-reflection template, peer-reflection template, technology integration questionnaire, online discussion forums and evaluation criteria form). As a result, this professional training particularly designed and implemented for the in-service English language instructors at tertiary level did make a change in their both technology integration and evidence-based multimodal reflective practice. Apart from the change in the instructors' technology integration, this study had an impact on their understanding, practice and quality of reflective practice involving evidence-based multimodal reflection tools as it helped the instructors to increase depth in their evidence-based multimodal reflective practice.