AbstractThis study focuses on the process of developing a learning environment that uses tablets and Quick Response (QR) codes to enhance participants' English language vocabulary knowledge. The author employed the concurrent triangulation strategy, a mixed research design. The study was conducted at a private school in Izmir, Turkey during the 2012-2013 academic year. The study sample was determined using the criterion sampling method. The criterion for selection was participants' possession of a mobile device. There were a total of 22 participants including one English teacher in the study, of which 12 were female and 10 male. The students' knowledge of English vocabulary was pretested using the Vocabulary Check List (VCL). During eight classes, participants completed English vocabulary activities using QR codes and tablet PCs. This learning environment integrated digital learning materials and real learning objects using QR codes. After the activities, students' knowledge of English vocabulary was again tested using the VCL, and the participants' opinions about the learning environment were solicited using semi-structured interviews. The research's qualitative data were analyzed using a descriptive analysis. The quantitative data were analyzed using the Wilcoxon signed-rank test and web analysis programs. The study found that the participants' overall rate of completing learning activities was low. The results of the VCL post-test indicated that participants' English language vocabulary knowledge had increases significantly. Participants' opinions regarding the learning environment were analyzed, and it was determined that although they had faced a few problems with the equipment, they experienced a general feeling of curiosity and excitement while using the environment. They found the environment entertaining and reinforcing, stating that learning environments of this kind should be used in other courses, too. The participant teacher stated that although the environment was effective there were a number of time management issues and caused difficulties in classroom management.Keywords: QR Codes * U-Learning * Ubiquitous learning * Learning English * Learning vocabularyIn the present day, English is one of the most important languages spoken, often finding itself as the second language in many countries whose native language is not English. In English language education, a variety of methods, techniques, and technologies are used to develop reading, listening, and speaking skills. As the popularity of using these new technologies increases, it has become increasingly important to provide learners with opportunities to learn English without restrictions of time or location.Language learning is based on vocabulary acquisition. Since students need to know the right words to express their thoughts without difficulty (Huang et al., 2012), considerable research on vocabulary learning has been done. With the development of computers and multimedia environments, a wide range of studies have used multimedia technologies, audio texts, and graphics to support vocabulary learning (Kim & Gilman, 2008; Sun & Dong, 2004). Mobile, wireless, and sensor technologies have been gradually integrated into educational activities, which has led to the establishment of learning environments that include high mobility and context awareness. Researchers have noticed that mobile and wireless technologies, such as multimedia technologies, are popular in language education. Chen and Chung (2008) developed an individualized mobile vocabulary learning system using palmtop computers. Huang et al. (2012) developed a u-learning system for English vocabulary, called UEVL (Ubiquitous English Vocabulary Learning). Laroussi (2004) developed a cyber-classroom called Ubi-Learn based on U-Learning in which he conducted a language course allowing students not only to attend in person or via a distance learning environment, but also to use computers or any mobile device in the class. …