Sea urchin injuries (SUIs) are among the most common marine injuries; however, there are no guidelines to dictate appropriate workup and treatment. Complications vary significantly depending on the extent of injury, site of injury and elapsed time to medical attention. Timely and appropriate management can prevent long-term morbidity despite the deceptively innocuous appearance of these injuries. We review the English literature on SUIs and offer an algorithm to aid in the management of affected patients. We found that superficially retained spines may trigger a local granulomatous inflammatory response, while spines retained near deep structures may induce sea urchin arthritis, inflammatory tenosynovitis, among other delayed complications. Therefore, we recommend immediate inactivation of pro-inflammatory compounds by hot water soaks at the time of injury, followed by extraction of all spines by a physician. Imaging is a valuable component of risk stratification to determine depth and location of spines, which guides selection of appropriate extraction technique to prevent long-term morbidity.