Previous reports which present methods of analysis of phenol and p-cresol by HPLC are usually designed for the detection of these compounds in urine, can be complicated by the use of uncommon equipment or additional techniques such as steam distillation or derivatisation, or concentrate on the detection of phenol rather than p-cresol. In this paper we report a simple method suitable for the analysis of phenol and p-cresol in both urine and feces, based upon extraction into ether following acid hydrolysis and UV detection.