A 42-year-old male was admitted to our hospital because of renal impairment. He had been well until three weeks earlier when he had developed a burning pain and hazy vision in his eyes. The ophthalmologist made a diagnosis of non-granulomatous anterior uveitis and prescribed topical corticosteroid. Two weeks after therapy uveitis improved but thereafter, nausea, vomiting, fatigue, anorexia and flank pain developed. During evaluation of his symptoms, he was detected to have elevated serum creatinine and was referred to nephrology department for further assessment. His past medical history, as well as family history, were unremarkable. He denied intake of analgesics or any indigenous medicine but upon further questioning, the patient admitted to using a synthetic cannabinoid, bonsai, over the prior few weeks. The patient was not critically ill, his appetite was good and there was no recent weight loss. His blood pressure was 140/90 mmHg, pulse 98 beats/ min, temperature 37.1°C. All the peripheral pulses were normal and equally palpable. The physical examination was essentially normal; there was no evidence of infection, he had no oedema or palpable lymph nodes and organomegaly. He had no abdominal bruit. The patient also underwent an ophthalmological examination that identified fine keratic precipitations consistent with previous anterior bilateral uveitis. A Schirmer's test performed was normal. Visual acuity was unimpaired and posterior segment examination was normal [Table/ Fig-1].His biochemical test results were compatible with acute renal failure {Blood Urea Nitrogen (BUN): 41 mg/dl; creatinine 2.6 mg/ dl}. Results of liver function tests and serum calcium, phoshorus, sodium, potassium and other electrolytes were within normal limits. In his blood gas analysis mild metabolic acidosis was detected due to renal impairment (pH:7.29 mmHg HCO 3 :19.8 mmol/L); he had a normal haemogram; an elevated erythrocyte sedimentation rate of 64mm/hour, C-reactive protein 24 mg/L (normal: < 5 mg/L). Urine density and pH were within normal ranges with renal glucosuria and absence of any morphologically abnormal cells in the urine sediment. The urine culture was sterile. Complement C3 and C4 levels were within normal limits, Antinuclear (ANA) and Antineutrophil Cytoplasmic (ANCA) antibodies, anti-Glomerular Basement Membrane (GBM) antibody, antibodies to DNA, rheumatoid arthritis factor, SS-A, SS-B, RNP, Sm, Jo-1, Scl70, hepatitis B surface antigen (Hbs Ag) and hepatitis C antibody ( HCV Ab) were negative.