CALL systems with ASR-technology may provide a solution for the growing need to support students' English communication skills at universities, but so far developments in this direction have been limited. MySpeechTrainer is an ASRbased CALL system intended to help students improve their general Academic English oral communication skills, as well as subject-specific vocabulary. In this paper we report on a study that evaluated the acceptance of MySpeechTrainer from the perspective of its target users. To this end, the 'Unified Theory of Acceptance and Use of Technology' (UTAUT) model, which is frequently used in ICT research, was employed to analyze students' acceptance and use of the new system. Two groups of students from Nijmegen and Utrecht universities used and reviewed MySpeechTrainer (N=87). Results of statistical analysis indicated that Social Influence was one of the main predictors of students' readiness to use the system. Participants were generally positive about MySpeechTrainer and indicated the need for more supportive and informative feedback.