Objective: To report on the effectiveness of sonographically guided injections of hyperosmolar dextrose at reducing the pain associated with chronic plantar fasciitis. Design: Case series. Setting: Ultrasound division of St Paul's Hospital. Patients: 20 referrals (3 men, 17 women; age 51 (SD 13) years) from local sports medicine primary care practitioners who had failed previous conservative treatments. Interventions: A 27-gauge needle administered a 25% dextrose/lidocaine solution under sonographic guidance at 6 week intervals returning for a median of three consultations. Main outcome measures: Visual analogue scale (VAS) items for pain levels at rest (VAS1), activities of daily living (VAS2), and during or after physical activity (VAS3) were recorded at baseline and at the final treatment consultation (post-test). A telephone interview conducted an average of 11.8 months after the post-test consultation provided a measure of long-term follow-up. Results: 16 patients reported a good to excellent outcome, while the symptoms in 4 patients were unchanged. There was a significant decrease (p<0.001) in all mean VAS items from pre-test to post-test: VAS1 (36.8 (SD 25.6) to 10.3 (10.9)), VAS2 (74.7 (20.8) to 25.0 (27.7)) and VAS3 (91.6 (9.2) to 38.7 (35.1)) and there were no apparent changes after the follow-up interview. Conclusions: Sonographically guided dextrose injections showed a good clinical response in patients with chronic plantar fasciitis insofar as pain was reduced during rest and activity. Further studies including a control group are needed to validate these outcomes.