International guidelines recommend salvage radiotherapy (sRT) as a curative treatment for men with biochemically recurrent prostate cancer after radical prostatectomy. Prostate-specific membrane antigen (PSMA) PET/CT has demonstrated high sensitivity for localizing recurrent disease at low prostate-specific antigen levels, enabling improved treatment decision-making. However, few studies have investigated the impact of pre-sRT PSMA PET/CT on patient-relevant outcomes, that is, recurrence-free and overall survival. Moreover, no comparison exists of overall survival between patients who underwent PSMA PET/CT and those who did not, before sRT. Methods: This study used real-world data (obtained from routine clinical practice) of all patients treated with sRT in Denmark from 2015 through 2023. Patients were categorized according to whether they underwent pretreatment PSMA PET/CT. Our main objective was to compare overall survival up to 5 y after completion of sRT. Biochemical recurrence–fre