Background Decision aids can be used to support shared decision making (SDM). A patient‐oriented treatment decision aid (DA) was developed for type 2 diabetes but its use by general practice staff appeared to be limited. Objectives To explore views of practice staff towards SDM and the DA. Design A mixed‐methods study within the Dutch PORTDA‐diab trial. Setting and participants Included were 17 practices with staff members who were responsible for routine diabetes care and had worked with the DA, and 209 of their patients. Methods Interviews were conducted focusing on applicability, usefulness and feasibility of the DA. Interviews were tape‐recorded, transcribed verbatim and subjected to content analysis for identifying and classifying views. Patient‐reported data about the use of the DA were collected. Associations between specific views and use of the DA were tested using Pearson point‐biserial correlation. Results The majority of practice staff expressed positive views towards SDM, which was associated with making more use of the DA. Most of the staff expressed that the DA stimulated a two‐way conversation. By using the DA, several became aware of their paternalistic approach. Some staff experienced a conflict with the content of the DA, which was associated with making less use of the DA. Conclusions The DA was considered useful by practice staff to support SDM. A positive view towards SDM was a facilitator, whereas experiencing a conflict with the content of the DA was a barrier for making use of the DA.