The purpose of this study was to develop an attitude and a self-efficacy survey of using PDAs in ubiquitous learning (u-learning) environments for elementary school students. The sample of this study included 414 third-grade to sixth-grade students (age 9-12 years) in Taiwan who had experience using PDAs for u-learning. The results indicate that the students, in general, had positive attitudes and adequate self-efficacy in terms of using PDAs for u-learning. Gender differences existed only in the students' self-efficacy of using PDAs for Internet related functions, with the male students expressing higher confidence in using PDAs for Internet-related functions than the female students. In addition, the students in lower grades (third and fourth-graders; age 9-10 years) tended to use PDAs more frequently and to have more positive perspectives of PDAs than the higher grade students (fifth and sixth-graders; age 11-12 years). Furthermore, for predicting students' attitudes toward using PDAs for u-learning, students' confidence in using PDAs for general purposes was more important than their confidence in using PDAs to perform Internet functions. (Contains 7 tables.)