BACKGROUND: Physical activity (PA) and nutrition are the cornerstones of diabetes management. Several reviews and meta-analyses report that PA independently produces clinically important improvements in glucose control in people with Type 2 diabetes. However, it remains unclear what the optimal strategies are to increase PA behaviour in people with Type 2 diabetes in routine primary care. METHODS: This study will determine whether an evidence-informed multifaceted behaviour change intervention (Movement as Medicine for Type 2 Diabetes) targeting both consultation behaviour of primary healthcare professionals and PA behaviour in adults with Type 2 diabetes is both acceptable and feasible in the primary care setting. An open pilot study conducted in two primary care practices (phase one) will assess acceptability, feasibility and fidelity. Ongoing feedback from participating primary healthcare professionals and patients will provide opportunities for systematic adaptation and refinement of the intervention and study procedures. A two-arm parallel group clustered pilot randomised controlled trial with patients from participating primary care practices in North East England will assess acceptability, feasibility, and fidelity of the intervention (versus usual clinical care) and trial processes over a 12-month period. Consultation behaviour involving fidelity of intervention delivery, diabetes and PA related knowledge, attitudes/beliefs, intentions and self-efficacy for delivering a behaviour change intervention targeting PA behaviour will be assessed in primary healthcare professionals. We will rehearse the collection of outcome data (with the focus on data yield and quality) for a future definitive trial, through outcome assessment at baseline, one, six and twelve months. An embedded qualitative process evaluation and treatment fidelity assessment will explore issues around intervention implementation and assess whether intervention components can be reliably and faithfully delivered in routine primary care. DISCUSSION: Movement as Medicine for Type 2 Diabetes will address an important gap in the evidence-base, that is, the need for interventions to increase free-living PA behaviour in adults with Type 2 diabetes. The multifaceted intervention incorporates an online accredited training programme for primary healthcare professionals and represents, to the best of our knowledge, the first of its kind in the United Kingdom. This study will establish whether the multifaceted behavioural intervention is acceptable and feasible in routine primary care. TRIAL REGISTRATION: Movement as Medicine for Type 2 Diabetes (MaMT2D) was registered with Current Controlled Trials on the 14th January 2012: ISRCTN67997502. The first primary care practice was randomised on the 5th October 2012.