Sea urchin injuries are common following accidental contact with sharp sea urchin spines. Immediate manifestations of injury include local erythema, pain, and myalgia. Failure to remove the spines from the skin may result in delayed systemic reactions, secondary infection, granulomas, and-if joint spaces are involved-inflammatory or infectious synovitis and arthritis. The majority of severe complications can be avoided if the spines are fully removed from the skin soon after injury, which can be difficult. This article aims to bring awareness to the myriad complications from sea urchin injuries as well as the mechanisms for successful spine removal.