We aimed to provide evidence on the trends and in-hospital outcomes of patients with low- and high-flow priapism through the largest study in the field. We used the GeRmAn Nationwide inpatient Data (GRAND), provided by the Research Data Center of the Federal Bureau of Statistics (2008-2021), and performed multiple patient-level analyses. We included 6,588 men with low-flow and 729 with high-flow priapism. Among patients with low-flow priapism, 156 (2.4%) suffered from sickle cell disease, and 1,477 (22.4%) patients required shunt surgery. Of them, only 37 (2.5%) received a concomitant penile prosthesis implantation (30 inflatable and 7 semi-rigid prosthesis). In Germany, the total number of patients with low-flow priapism requiring hospital stay has steadily increased, while the number of patients with high-flow priapism requiring hospital stay has decreased in the last years. Among patients with high-flow priapism, 136 (18.7%) required selective artery embolization. In men with low-flow priapism, sickle cell disease was associated with high rates of exchange transfusion (OR: 21, 95% CI: 14–31, p < 0.001). The length of hospital stay (p = 0.06) and the intensive care unit admissions (p = 0.9) did not differ between patients with low-flow priapism due to sickle cell disease versus other causes of low-flow priapism. Accordingly, in men with high-flow priapism, embolization was not associated with worse outcomes in terms of length of hospital stay (p > 0.9), transfusion (p = 0.8), and intensive care unit admission (p = 0.5). Low-flow priapism is an absolute emergency that requires shunt surgery in more than one-fifth of all patients requiring hospital stay. On the contrary, high-flow priapism is still managed, in most cases, conservatively.