Hematuria is a concerning sign that warrants evaluation because it may signal the presence of a genitourinary malignancy. Full urologic evaluation for hematuria must be done after excluding pseudohematuria, history of nephrological pathology, trauma, or recent urologic manipulation. One of the rare causes of gross hematuria: hereditary hemorrhagic telangiectasia (HHT) that must be considered in the differential diagnosis of haematuria of unknown cause. In this case we describe a rare primary presentation of hereditary hemorrhagic telangiectasia with painless gross haematuria and urethral bleeding. We present a case of a 21-year-old Saudi male with a history of painless gross haematuria and urethral bleeding. Urinary tract infection (UTI), nephropathy and bleeding diathesis had been investigated and were excluded. Computed tomography (CT) scan showed no pathological lesions. The patient underwent urethro-cystoscopy and multiple telangiectatic lesions were observed in the penile urethra and in the trigone of the bladder. We also found another telangiectasias lesion in the oral mucosa. With these findings, this patient was diagnosed with probable HHT based on Curaçao’s diagnostic criteria. However, other differential diagnoses other than solitary telangiectasia of the bladder were excluded. HHT, despite a rare cause, must be considered in the differential diagnosis of haematuria of unknown cause. Conservative management with close follow up to prevent complications can be a potential line of management in these cases with stable condition before proceeding to medical or surgical treatment.