Ultrasound-guided transperineal prostate brachytherapy is now widely used modality in the treatment of prostate cancer. The overall prostate-specific antigen (PSA) progression-free survival at 10 years is 80-90% for low-risk patients. The results of long-term follow-up have showed better biochemical disease-free survival after I-125 and Pd-103 brachytherapy than after conventional external-beam radiotherapy and similar survival after radical prostatectomy. The most commonly reported dosimetric quantifiers include D90 (the dose that covers 90% of the prostate volume outlined on postimplant computed tomography images) and V100 (the fractional volume of the prostate that receives 100% of prescription dose). The biochemical disease-free survival correlates with the dose. In low-risk patients, achieving a D90 dose of 140-160 Gy might be adequate for prostate-specific antigen control. However, high-risk disease might require a D90 dose higher than 200 Gy. In the immediate posttreatment period, the most common complication is acute urinary retention. Urinary symptoms such as frequency, nocturia, and dysuria occur commonly and are documented in about 80% of patients complaining of symptoms 2-3 months after treatment. Late urinary complications of brachytherapy include urethral stricture and incontinence. Incontinence is rare and mainly occurs in patients who had transurethral resection of the prostate either prior or after brachytherapy. Rectal complications (proctitis, rectal bleeding) are rare after prostate brachytherapy. Brachytherapy like external-beam radiotherapy but unlike surgery preserves ejaculation; potency rates also appear to be relatively high after brachytherapy, at 50-85%, and most patients' sexual quality and function are preserved. Since July 2007, the real-time I-125 prostate brachytherapy has been started in Lithuania and Baltic countries at the Hospital of Kaunas University of Medicine. A total of 150 low-risk patients (< or =T2a, Gleason < or =6, PSA < or =10) were treated by this method. Permanent prostate brachytherapy is an appropriate method for standard treatment of localized prostate cancer.