Mobile technologies such as multimedia guides (MMGs) are now an important part of the visitor experience in museums and other cultural spaces. We report the development of two scales to measuring visitors’ museum experiences: the Museum Experience Scale (MES) and the Multimedia Guide Scale (MGS); these quantitative measures can helpfully complement qualitative information about visitor experience. A standard psychometric methodology was used in the development of these scales: from a large set of potentially relevant statements, 57 were chosen and 255 people rated a museum experience (102 of whom had used a multimedia guide). A Principal Components analysis yielded a four factor solution for the MES (Engagement, Knowledge/Learning, Meaningful Experience and Emotional Connection) and a three factor solution for the MMGS (General Usability, Learnability and Control, Quality of Interaction). Comparing respondents who used a MMG during their museum visit with those who did not, there was a significant difference on the Engagement component of the MES, with respondents who used a MMG being significantly more engaged. The other components of the MES did not show significant differences.