Mescaline is a psychoactive hallucinogenic alkaloid that resemble the natural neurotransmitters epinephrine and dopamine. It is extracted from peyote cactus. Peyote cactus cannot be detected via blood or urine samples in routine toxicology laboratories, and it can be easily reachable over the Internet. In this report, we presented the first case of mescaline abuse via peyote cactus in Turkey. The case is an 18-year-old male patient. He was subjected to probation service due to use of cannabis for three months by the court decision, and being treated in our forensic outpatient clinic. He was admitted to the emergency service with symptoms such as intense anxiety, panic attacks and visual hallucinations. Patient told that he consumed peyote cactus instead using cannabis not to get caught in urine analyze.