To address questions about the importance of public (patients, patient groups, etc) engagement in HTA processes with the objective to – 1) explore ideas regarding the use of public engagement in decision making processes (specifically coverage decisions), and 2) contextualise some of the main arguments found by assessing the Canadian Agency for Drugs and Technologies in Health’s (CADTH) current public engagement mechanisms for its Common Drug Review (CDR). A literature search was performed to identify key theoretical arguments for and against public engagement in HTA processes. The search was mainly focused on sources from Canada and the UK. A review of CADTH’s website was conducted for technology appraisals completed by the CDR process since the start of its public engagement initiatives (to mid-August 2012). Key arguments for public engagement in decision making include: transparency, accountability, equity, and creating a patient-centric health system. With the CDR, the percentage of appraisals conducted for coverage decisions that included public (patient group) input was 48%. The lack of engagement from patient groups on half of the appraisals highlights some of the key challenges of public engagement (e.g., lack of awareness, lack of budget). Furthermore, the documents reviewed showed that some indications received more responses than others (e.g., epilepsy, schizophrenia). This may potentially result in some underfunded patient groups feeling disempowered, which is a risk of engagement. The findings of the study support initiatives that encourage the engagement of the public so that decision makers can better incorporate the values held by citizens. However, the relative value of doing so will vary. To ensure that public engagement in HTA is appropriate and fair, Canada and other jurisdictions must have political will, dedicated resources, and the motivation to facilitate educational activities that support active engagement from all types of public.