Use of cannabinoids is increasing at an alarming rate. Their easy availability, cheapness, perceptive legality and difficulty in detecting its presence with standard urine toxicologic tests, and similar factors probably contribute to the increased use, and popularity of synthetic cannabinoids. Although laws, and regulations concerning auditing of these substances have been implemented in many countries, production of new types of synthetic cannabinoids rapidly takes place. Primary psychoactive ingredient of cannabis is Δ 9-tetrahydrocannabinoid which is partial agonist of cannabinoid receptors, while synthetic cannabinoids are potent, and complete agonists of these receptors. Therefore it is not surprising that synthetic cannabinoids exert more powerful effects than cannabinoids. Clinical effects of synthetic cannabinoids can cause referrals to emergency services, and hospitalizations. Despite lack of any specific therapy benzodiazepines, antipsychotics, and fluid replacement may be required. Clinical follow-up studies are needed for better comprehension of its clinical effects, and treatment outcomes.