Background. To date the efficacy and acceptability of internet-delivered cognitive behavioural treatments (iCBT) has been examined in clinical trials and specialist facilities. The present study reports the acceptability, feasibility and preliminary efficacy of an established iCBT treatment course (the Wellbeing Course) administered by a not-for-profit non-governmental organisation, the Mental Health Association (MHA) of New South Wales, to consumers with symptoms of anxiety.Methods. Ten individuals who contacted the MHA’s telephone support line or visited the MHA’s website and reported at least mild symptoms of anxiety (GAD-7 total scores ≥5) were admitted to the study. Participants were provided access to the Wellbeing Course, which comprises five online lessons and homework assignments, and brief weekly support from an MHA staff member via telephone and email. The MHA staff member was an experienced mental health professional and received minimal training in administering the intervention.Results. All 10 participants completed the course within the 8 weeks. Post-treatment and two month follow-up questionnaires were completed by all participants. Mean within-group effect sizes (Cohen’s d) for the Generalized Anxiety Disorder 7 Item (GAD-7) and Patient Health Questionnaire 9 Item (PHQ-9) were large (i.e., > .80) and consistent with previous controlled research. The Course was also rated as highly acceptable with all 10 participants reporting it was worth their time and they would recommend it to a friend.Conclusions. These results provide support for the potential clinical utility of iCBT interventions and the acceptability and feasibility of employing non-governmental mental health organisations to deliver these treatments. However, further research is needed to examine the clinical efficacy and cost-effectiveness of delivering iCBT via such organisations.