Biochemical failure after radical treatment for prostate cancer occurs in up to 30% – 50% of cases. Localisation of clinical disease is challenging because clinical symptoms often manifest long after the initial rise in prostate-specific antigen. The detection rates of imaging modalities such as contrasted computed tomography (CT), bone scan, magnetic resonance imaging and choline positron-emission tomography (PET) or CT, are limited. Prostate-specific membrane antigen (PSMA) ligand PET or CT is a novel imaging modality under investigation for various diagnostic and therapeutic indications in the management of prostate cancer. We present a case report illustrating how <sup><span style="font-size: small;">68</span></sup>Gallium-PSMA ligand PET or CT was used to guide management in a patient presenting with biochemical failure after radical prostatectomy.