The study of workplace learning and informal learning are not new to adult education and pedagogy. However, the use of mobile devices as learning tools for informal learning in the workplace is an understudied area. Using theories on informal learning and constructivism as a framework, this paper explores informal learning of registered nurses using mobile devices to meet their learning needs for continuing professional education, professional development, and continuing competence within the challenging healthcare workplace. In this mixed methods study, participants used their devices for self-directed informal learning with non-collaborative strategies/processes for evidence-based support, new procedures/treatments, professional development, patient/client teaching, and maintaining competency. Positive perceptions were articulated. Minimal differences were associated to the nurses' age. However, workplace-related influences were relevant to the informal learning experiences with the mobile devices.