The aim of this study was to describe the self-reported and analytically detected recreational substances of Geneva University Hospitals Emergency Division patients and to assess the relevance of developing new analytical tools to identify New Psychoactive substances compounds. This was a retrospective descriptive analysis on patients’ computerized files between July 1 2019 and June 30 2021. During the study period, 826 treatment episodes were related to acute recreational substance use. Mean patient age was 35 years and 77% were male. Alcohol co-ingestion was reported in 54% and multiple drug use in 40% of the cases. Cocaine, sedatives and cannabis were the most reported drugs. The most detected substances with immunoassays were cocaine (38%), benzodiazepine (50%) and cannabis (24%). New psychoactive substances were reported 11 times, and analytically detected with mass spectrometry in 5 samples, which were positive for 3 synthetic cathinones (3-MMC, 4-MMC, methcathinone) and one synthetic benzodiazepine (etizolam). Although conventional recreational drugs, along with alcohol and multiple drug use, are the major contributors to emergency admission, New Psychoactive Substances have been found in an unexpected number of cases. However, they remain potentially underdiagnosed due to analytical limitations. In light of the toxicity risks associated with these compounds and in the context of the acquisition of new analytical equipment, the development of detection methods seems justified.