The main thesis of this study is that since 1990 South Africa has conducted its nuclear diplomacy by constructing certain norms and its identity in a particular way to serve its national interests. A constructivist analysis of South Africa’s nuclear diplomacy concerning the nuclear non-proliferation export control regimes; the International Atomic Energy Agency (IAEA); the Pelindaba Treaty; and the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) suggests that South Africa’s application of three typical middle power diplomatic strategies, namely confrontation, cooperation and parallelism have enabled the country to secure a niche role for itself that has provided the country with some material and non-material rewards. South Africa’s membership of some of the major nuclear export control regimes reflects its socialisation of the norms of non-proliferation, disarmament, and the peaceful uses of nuclear energy. South Africa has incorporated aspects of this regime in its nuclear export trade policies and national nuclear-related institutions. Despite this, the South African government’s efforts were undermined by a series of contentious nuclear proliferation-related incidents, most notably the involvement of South Africans in the AQ Khan network. South Africa was a founder member of the IAEA in 1957. Despite this early role in norm construction, South Africa’s relations with the IAEA deteriorated as international opposition to its apartheid policies escalated. Defying international isolation, the country embarked on a nuclear weapons programme that produced six atomic devices. South Africa returned to its designated seat for Africa on the IAEA Board of Governors in 1995. A vocal opponent of the discriminatory nature of the IAEA Statute and supporter of all countries’ right to the peaceful uses of nuclear energy, South Africa’s influence in the Agency expanded. Despite this, the country’s candidate for the position of IAEA Director General was not elected. Africa’s position on nuclear non-proliferation originated in the 1960s. Once South Africa’s domestic policies became known and suspicions of its nuclear weapons programme grew, the Organisation for African Unity (OAU) turned its focus to condemnation of South Africa. As a result of the political transition in South Africa; its ratification of the NPT; and the IAEA’s verification process, South Africa joined Africa to establish the African nuclear weapons free zone in terms of the Pelindaba Treaty. As a result the country was elected to chair and host the AFCONE. Despite its historical opposition to the NPT, the country ratified the Treaty in 1991 and has constructed its niche role in the NPT regime through its problem-solving and bridge building roles at various NPT conferences. Therefore, this study concludes that South Africa’s post-1990 nuclear diplomacy has maintained a normative foundation; employed various diplomatic strategies; and was conducted in compliance with the set objectives of the country’s foreign policy. In this, the analysis of the nuclear diplomacy of a state such as South Africa, which discontinued its nuclear weapons programme, provided insights into nuclear diplomacy in general and the nuclear diplomacy of states similar to the South African situation.