In this study, a peer assessment-based mobile learning approach was implemented and evaluated in a vocational design certification course. A quasi-experiment was conducted to explore the impact of the proposed approach on the learning achievements and motivations of the students with active and reflective styles. It was found that the students using the peer assessment-based mobile learning approach generally learned better than those using the conventional mobile learning approach. It was also found that there were interactive effects between learning approaches and learning styles on intrinsic motivation. The students with an active learning style outperformed those with a reflective style in intrinsic motivation when conducting the peer assessment-based mobile learning. Active learning style students also had higher extrinsic motivation than those with a reflective learning style when conducting mobile learning.