The availability and use of 3D treatment planning facilities in the UK was investigated by questionnaire. Fifty-eight of the 62 UK radiotherapy centres responded (94%). There was considerable variation in the facilities available and in the manner in which they were used. Although 36 centres (62%) have the facilities to undertake complex, non-coplanar treatment planning, only 12 did so on a regular basis. More surprising was the inconsistent implementation of coplanar CT planning. It is suggested that we need to work towards reaching a consensus on best practice in radiotherapy planning. This will require the creation of systems for guidance and further training of the various staff involved.