Abstract Introduction In recent years, therapeutic approaches for treating vasculogenic Erectile Dysfunction (ED) have evolved, with Low Intensity Shock Wave Therapy (LISWT) emerging as a promising modality. Objective To objectively evaluate the efficacy of LISWT for ED patients and to predict the required number of sessions, we examined the effects of administering up to 10 mcg of intracavernous alprostadil injections both before and after treatment Methods 85 vasculogenic ED patients (Average age: 57); 33 with mild to moderate ED and 52 with moderate or severe ED. Intracavernous injection (ICI) of ≤10 mcg of alprostadil was given before LISWT and one month post-treatment. Depending on ICI response, patients underwent either six (Erection Hardness Score (EHS) ≤3) or four (EHS=4) weekly LISWT sessions using PiezoWave2 from Richard WOLF. LISWT Parameters: 0.16mj/mm2 energy flux density, 8 Hz frequency, 10mm wave focus penetration depth, and 6000 shocks per session distributed among the two crura of the penis (2000 shocks), dorsum penis (2000 shocks), and lateral penis (2000 shocks). Results 33 patients showed a robust response to the 10mcg ICI and were treated with four LISWT sessions. 52 patients exhibited a partial response to the 10mcg ICI, necessitating six LISWT sessions. 78.6% (26 out of 33) of the patients who initially responded well to 10 mcg ICI had a consistent response to 8 mcg ICI; 63.6% (33 out of 52) of those with a partial initial response to 10 mcg ICI demonstrated an improved reaction to the same dosage post-treatment (table 1) (fig. 1). No complications were reported from the ICI. Conclusions Intracavernous prostaglandin injection can serve as a predictor for the required number of LISWT sessions and can objectively gauge the treatment's effectiveness in ED patients. Further randomized studies, incorporating parameters such as EHS, IIEF, and the ICI dosage, are recommended to validate this method's feasibility Disclosure No.