Stromal tumour of uncertain malignant potential (STUMP) is exceedingly rare. Diagnosis and management of STUMP present a challenge to the urologist due to the absence of specific clinical findings and its unpredictable clinical course. Thus, radical resection is often recommended. Here, we present a case of a 64-year-old male, who presented with mild obstructive voiding symptoms with a raised age-specific prostate-specific antigen (PSA) of 3.1. Magnetic resonance imaging (MRI) showed an area of suspicion, in an area thought to be the left seminal vesicle, containing a malignant lesion within it. Biopsy of this area and the prostate confirmed concurrent prostatic STUMP and Gleason 3+3=6 adenocarcinoma of the prostate, managed with robotic-assisted laparoscopic radical prostatectomy with wide local excision.