Synthetic marijuana, a synthetic psychoactive substance that causes similar effects as cannabis, is one of the most used illicit drugs in the world. Various terms have been used for these preparations, including SPICE, K2, and SPICE GOLD. On the streets it is called ‘bonsai’. Synthetic cannabinoid preparations are more potent and bind more avidly than cannabis to the cannabis receptors in the brain. They have neurologic, cardiovascular, renal and sympathomimetic effects. We report here two previously healthy young men presenting with acute kidney injury (AKI) after using bonsai. Synthetic cannabinoid use should be considered when an otherwise healthy young male presents with AKI. We suggest that synthetic cannabinoids have the potential to be extremely harmful due to their method of manifacture and high potency. The full danger of these drugs has not yet been determined.