The standard treatment for muscle-invasive bladder cancer (MIBC) is a radical cystectomy with pelvic lymph node dissection with or without neoadjuvant chemotherapy. In selected cases a bladder sparing approach is possible, for example a limited surgical excision combined with external beam radiotherapy and brachytherapy. To perform brachytherapy flexible catheters have to be implanted in the bladder wall. The implantation is done either by the open retropubic approach or the endoscopic surgical approach. The largest experience for brachytherapy is with low-dose rate and pulsed-dose rate, although some short-term experience with high-dose rate is also reported. The main advantage for this technique is the conservation of bladder function, with comparable local control rates as for cystectomy series in selected cases. The GEC-ESTRO/ACROP (Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology / Advisory Committee on Radiation Oncology Practice) recommendations to perform bladder implantations and brachytherapy as a treatment option for MIBC are described.