Objective - The primary objective was to ascertain the therapeutic usefulness of homeopathic medicine in the management of chronic sinusitis (CS).Materials and methods - Multicentre observational study at Institutes and Units of the Central Council for Research in Homoeopathy, India. Symptoms were assessed using the chronic sinusitis assessment score (CSAS). 17 pre-defined homeopathic medicines were shortlisted for prescription on the basis of repertorisation for the pathological symptoms of CS. Regimes and adjustment of regimes in the event of a change of symptoms were pre-defined. The follow-up period was for 6 months. Statistical analysis was done using SPSS version 16.Results - 628 patients suffering from CS confirmed on X-ray were enrolled from eight Institutes and Units of the Central Council for Research in Homoeopathy. All 550 patients with at least one follow-up assessment were analyzed. There was a statistically significant reduction in CSAS (P = 0.0001, Friedman test) after 3 and 6 months of treatment. Radiological appearances also improved. A total of 13 out of 17 pre-defined medicines were prescribed in 550 patients, Sil. (55.2% of 210), Calc. (62.5% of 98), Lyc. (69% of 55), Phos. (66.7% of 45) and Kali iod. (65% of 40) were found to be most useful having marked improvement. 4/17 medicines were never prescribed. No complications were observed during treatment.Conclusion - Homeopathic treatment may be effective for CS patients. Controlled trials are required for further validation.