A group of Swedish oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. If an estimated 1% of the palliative treatments can be administered by protons with substantial benefits to the patient, almost 100 patients per year in Sweden would be eligible. It is further estimated that around 150 patients per year in need of reirradiation would benefit from radiation with protons compared to photons.