The use of mobile devices in an educational context to support learning has drawn considerable attention, however, there is relatively little systematic knowledge about how it can be used effectively as a knowledge acquisition tool in workplace environments. This paper proposes mobile learning (m-learning) as a just-in-time learning tool to support and manage ICT problem related calls in a Science Museum (SM). Employees' intention to use m-learning is investigated using the Unified Theory of Acceptance and Use of Technology (UTAUT) model. Selected UTAUT factors including performance expectancy, effort expectancy, social influence and facilitating conditions are analysed to explain the determinants of m-learning adoption at the SM. Results demonstrate that the selected UTAUT factors had a significant impact on employee's behavioral intention to use m-learning at the SM. Further examination found age and gender moderate the relationship between the UTAUT factors. These findings present several useful implications for m-learning research and practice for ICT service desks.