A number of forms of radiation therapy are now commonly used for the treatment of low-risk prostate cancer (LRPCa). The tumour control rates are typically excellent, and the risk of death from prostate cancer very low regardless of the treatment modality. This is despite there being a paucity of prospective evidence with which to guide the radiation oncologist in this particular disease subtype. Much of the decision-making will fall back to evidence extrapolated from much more advanced or high-grade malignancy, while our current understanding of comorbidities poorly illuminates the initial question of whether or not the patient requires radical treatment at all. The number of variables in the treatment selection algorithm continues to increase, with a virtually unending array of treatment options when one combines the available variations in radiation modality, technique, dose and dose fractionation. All treatment is associated with a risk of toxicity, and there are substantial differences in the toxicity seen between the modalities. A number are strongly associated with pre-existing conditions and can be seen as relative contraindications to either a specific radiation modality, or any treatment in general. This article aims to review data regarding LRPCa and radiotherapy outcomes, and highlight the potential challenges to improve this data in a planned manner.