Introduction and Purpose The need for aggressive efforts to help tobacco users quit remains a healthcare priority. Brief interventions delivered in the healthcare environment continue to be a valuable component of a comprehensive tobacco control policy. Unfortunately, such treatments are offered less often than desired, and quality is variable. Previous research has demonstrated the value of training experiences in increasing treatment availability, quality, as well as improving clinical outcomes. Less is known about how specific clinical activities and other features are impacted as a function of training. These issues were explored within the context of a standardised 5A's (ASK, ADVISE, ASSESS, ASSIST, ARRANGE) brief intervention training program. Methods A variety of healthcare providers participated in this study. Survey methodology was employed to collect Practice Behaviour, Self-Efficacy and Attitude ratings at pretraining, post training and 6-month follow-up. Linear mixed effects models were used to evaluate primary outcomes, and linear regression to explore the relationships among clinical variables. Results Pretraining data suggested overall modest levels of tobacco treatment activity, with limited direct intervention (ASSIST) or follow-up (ARRANGE) efforts. The training experience was shown to have a substantial and sustained impact on 5A's Practice Behaviour ratings, and other clinical indicators (all Pre vs. Post and Pre vs. Follow-up comparisons p < 0.001). Self-Efficacy at post training predicted practice behaviours at follow-up (for ADVISE, ASSESS, ASSIST and ARRANGE: all p's < 0.05). Conclusions The value of a structured training experience was confirmed, and findings served to clarify the specific nature of training program impact. © 2014 John Wiley & Sons Ltd.