Summary Background Stereolithographic (SL) biomodelling allows 3D CT to be used to generate solidplastic replicas of anatomical structures (biomodels). Case reports in the literature suggest that such biomodels may have a use in craniofacial surgery but no large series or assessment of utility has been reported. A prospective trial to assess the utility of biomodelling in craniofacial surgery has been performed. Methods Forty patients with complex craniofacial abnormalities were selected and 3D CT scanning performed. The data of interest was used to guide a laser to selectively polymerise photosensitive resin to manufacture SL biomodels. The biomodels were used for patient education, diagnosis and operative planning. An assessment protocol was designed to test the hypothesis that biomodels in addition to standard imaging had greater utility in the surgery performed than the standard imaging alone. Results Anecdotally surgeons found biomodelling useful in 40 complex craniofacial operations. The formal assessment of the first 10 cases suggested biomodels improved operative planning (image 76%, image with biomodel 97%, P<0.01) and diagnosis (image 82.5%, image with biomodel 99.25%, P<0.01). Surgeons estimated that the use of biomodels had reduced operating time by a mean of 16% and were cost effective at a mean price of $1100 AUS. Conclusion Biomodelling was reported as an intuitive, user-friendly technology that facilitated diagnosis, operative planning and communication between colleagues and patients. Limitations of the technology were manufacturing time and cost.