Worldwide, radiographers' radiation protection practices vary. In South Africa, evidence of diagnostic radiographers' suboptimal radiation protection practices has been reported, but the reasons for these practices and suggestions to improve practices were lacking. Therefore, this study explored radiation protection among South African diagnostic radiographers. This study used an explanatory, sequential, mixed-method approach. Data were collected in three phases. Phase I, the quantitative phase, used an online questionnaire and respondents from Phase I interested in participating in Phase II, the qualitative phase, were interviewed, yielding 13 in-depth semi-structured telephone interviews. In Phase III, eight radiography managers co-constructed change strategies to optimize radiation protection in South Africa in two focus group interviews. Radiation protection was suboptimal despite diagnostic radiographers having a good attitude, subjective norm and perceived behavioral control toward radiation protection and optimal radiation protection knowledge. Varying attitudes to radiation protection, lack of resources, and support from radiography management and healthcare teams contributed to suboptimal radiation protection practices. Radiography managers suggested increasing radiation protection awareness, ameliorating the diminished stature of the radiographer in the healthcare team, and increasing the availability of optimal quality resources. South African diagnostic radiographers' radiation protection knowledge was optimal, but the implementation of radiation protection varied and was influenced by multiple factors. A radiation protection culture supported by management is advocated to optimize radiation protection. However, ultimately radiation protection practices are incumbent on the individual radiographers' choice to practice radiation protection.