A case study comparing three-dimensional conformal radiation therapy with field-in-field (FiF) technique and volumetric-modulated arc therapy (VMAT) for head/neck (H/N) irradiation, evaluating the differences in the treatment techniques and low doses to critical structures. Compared to VMAT plan, 3D FIF plan offers similar planning target volume coverage and acceptable organs at risk dose. Therefore, 3D FIF is still a feasible alternative for some centres unqualified for IMRT/VMAT worldwide.