A middle-aged Indian woman with knee pain had consumed ayurvedic medicine (Ostolief and Arthrella tablets) daily for 6 months. She presented to the respiratory clinic with worsening dyspnea, cough and weight loss of 2 months' duration. She was a homemaker, never-smoker and did not keep birds. Physical examination detected fine end-inspiratory crackles. There was no clubbing of the fingers, joint deformity or swelling, skin lesion or enlarged cervical lymphadenopathy. High-resolution computed tomography showed diffuse centrilobular nodules with ground-glass attenuation. Restrictive ventilatory defect (FVC 44% predicted, FEV₁/FVC ratio 93%) was observed on spirometry, and the autoimmune screen was negative. Bronchoalveolar lavage fluid revealed lymphocytosis with an increased CD4/CD8 (T helper:T suppressor) ratio. Cultures for bacteria, mycobacteria, fungi, viruses and <i>Pneumocystis carinii</i> were negative. Alveolitis with infiltration of interstitium by lymphocytes and peribronchiolar noncaseating granulomas were observed on bronchoscopic lung biopsy. A diagnosis of hypersensitivity pneumonitis as a result of ayurvedic medicine was made. She was advised to stop the offending medicine; high-dose steroids and bactrim prophylaxis were commenced and tapered over 3 months with good response and radiological resolution. She was followed for 1 year without relapse.