Background: Hemostasis in critically ill patients represents a fragile balance between hypocoagulation and hypercoagulation, and is influenced by various factors. Perioperative use of extracorporeal membrane oxygenation (ECMO)—increasingly used in lung transplantation—further destabilizes this balance, not least due to systemic anticoagulation. In the case of massive hemorrhage, guidelines recommend considering recombinant activated Factor VII (rFVIIa) as an ultima ratio treatment only after several preconditions of hemostasis have been established. These conditions are calcium levels ≥ 0.9 mmol/L, fibrinogen levels ≥ 1.5 g/L, hematocrit ≥ 24%, platelet count ≥ 50 G/L, core body temperature ≥ 35 °C, and pH ≥ 7.2. Objectives: This is the first study to examine the effect of rFVIIa on bleeding lung transplant patients undergoing ECMO therapy. The fulfillment of guideline-recommended preconditions prior to the administration of rFVIIa and its efficacy alongside the incidence of thromboembolic events were investigated. Methods: In a high-volume lung transplant center, all lung transplant recipients receiving rFVIIa during ECMO therapy between 2013 and 2020 were screened for the effect of rFVIIa on hemorrhage, fulfillment of recommended preconditions, and incidence of thromboembolic events. Results and Discussion: Of the 17 patients who received 50 doses of rFVIIa, bleeding ceased in four patients without surgical intervention. Only 14% of rFVIIa administrations resulted in hemorrhage control, whereas 71% of patients required revision surgery for bleeding control. Overall, 84% of all recommended preconditions were fulfilled; however, fulfillment was not associated with rFVIIa efficacy. The incidence of thromboembolic events within five days of rFVIIa administration was comparable to cohorts not receiving rFVIIa.