A 3.5-year-old Vietnamese boy presented with precocious pseudopuberty, hypertension and a skin rash that was treated with Vietnamese medications for 6 weeks, with resolution. Serum androgen levels were prepubertal, adrenal ultrasound was normal but a large unknown abnormal peak was detected in the urine steroid profile. Cessation of medications disclosed elevation of plasma androgen and 11-deoxycortisol levels. The unidentified urine steroid profile peak disappeared and a tetrahydro-11-deoxycortisol peak was detected. This patient represents a difficult and challenging diagnosis of 11beta-hydroxylase deficiency. Careful evaluation of history and physical finding in the presence of apparent biochemistry discrepancy resulted in a correct diagnosis.