The Mombello Psychiatric Hospital in Limbiate, near Milan, replaced the old Senavra Hospital as the Psychiatric Hospital for the Province of Milan in the 19th century. During the early 20th century, bodies of several Mombello patients were dissected and preserved by Giuseppe Paravicini, an anatomist who operated within the asylum. The aim of the present study was to examine and valorize this important assemblage. To this end, we were allowed to sample the head hair of six such preparations for toxicological analysis. By means of high performance liquid chromatography, cocaine and its main metabolite, benzoylecgonine, were detected in two out of six hair samples. The concentrations for cocaine were 0.151 and 0.09 ng/mg and for benzoylecgonine 0.103 and 0.147 ng/mg, respectively. Given that cocaine was a commonly used medicine beginning in the mid-19th century and persisting into the 20th century, it is not surprising that some patients may have ingested this drug. In addition to the detection of cocaine, these analyses also provided evidence of nicotine and caffeine intake.