White piedra is a clinical condition caused by Trichosporon species (1,2). The most distinctive feature of this mycosis is the production of white-brown nodules adhered to the hair shaft that may easily be detached, in contrast to black piedra nodules (3). Despite awareness of white piedra in the medical field since the 19th century (4), there is little knowledge about its mechanisms of infection in humans (5,6). Furthermore, it may occur more frequently than current estimates report, especially in tropical countries where it is believed that underdiagnosis occurs (5). No published studies have explored the chemical nature of white piedra nodules, but the observation of ultrastructural parasitism has been described (7,8). Here, we present the first in vitro study of white piedra with associated ultrastructural and chemical analyses.This article is protected by copyright. All rights reserved.