Patients with plantar fasciitis and pain refractory to conventional therapy are treated with low-dose radiotherapy (RT), but no conclusive evidence-based and radiobiological studies had been performed. In 2001 the German Cooperative Group on Radiotherapy for Benign Diseases (GCG-BD) carried out a study by mailing a standardized questionnaire. A total of 136 institutions treated 3621 patients/year with chronic or refractory pain. The median total dose was 6 Gy (median single dose: 1 Gy); 76 institutions reported data of their clinical evaluation of a total of 7947 patients. Pain relief lasting for at least 3 months was reported in 70% and persistent pain relief in 65%. There were no acute or chronic radiogenic side effects observed. The radiobiological studies showed a significant increase of granulocyte function at 1.5 Gy and a significant decrease at 3.5 and 4.0 Gy. These results may provide a possible explanation for a local anti-inflammatory effect of low-dose RT. RT may be an excellent alternative for patients with contraindications to long-term treatment with steroids or NSAID.