This paper investigates Kazakhstan’s position in the Shanghai Five and Shanghai Cooperation Organisation (SCO), focussing on multilateral security mechanisms and sustainable regional development. This study uses qualitative analysis of SCO documents, legal texts, and United Nations Office on Drugs and Crime data to examine Kazakhstan's role in regional security and sustainable development. It was noted that the main objectives of the “five” in the 1990s were to establish trusting relationships to prevent military and border conflicts in Central Asia. It is analysed that separatist rallies took place in the northern regions of Kazakhstan in the mid and late 1990s, but the provisions of the Shanghai Convention on Combating Terrorism, Separatism, and Extremism helped to minimise separatist phenomena in Kazakhstan. The provisions of the Agreement of the SCO in 2004 became important for such changes, where a role was given to the development of a health protection system. Counteraction to the transportation of narcotic substances in Kazakhstan was extremely weak since 730 kg of heroin were seized in 2009 and 323 kg – in 2010, considering 70-75 t of heroin that arrived in transit to Kazakhstan in 2010. The findings reveal that Kazakhstan’s SCO engagement shows a regional cooperation model that links security governance to sustainability, resilience, and equitable development. The data also shows that institutional corruption and law enforcement’s ineffective narcotics control continue to impair sustainable outcomes.