The aim of this study was to make an economic analysis and evaluation of a low-cost virtual surgical planning (VSP) protocol that was developed in house, and based on open-source software and a desktop 3-dimensional printer. All eight patients between April 2014 and 2015 who had been treated by mandibular reconstructions with microvascular fibular flaps that had been planned using the protocol were retrospectively analysed for accuracy, time, and cost. Median differences for planned compared with postoperative intercondylar distance, intergonial distance, and gonial angle did not differ significantly. A median (range) labour time of 85 (€57-124) minutes was needed. An evaluation of cost, including labour, showed an additional median (range) cost/patient of € 276 (€257.50-297.25). With the acquisition cost of the 3-dimensional printer omitted, there was a negligible additional cost/patient of €44.75 (€26.25-66). All planning was done by the junior surgeon and there was a steep learning curve. Our new VSP protocol is cost-effective, easy to use, and has an accuracy comparable with that of a standard VSP protocol. To the best of our knowledge this is the first report of an open-source software protocol in which the labour costs of the planning by a surgeon are included.