This article discusses the significant impact of the two crucial moments in Indonesia namely, the 1965 coup and reformasi (reformation) in May 1998 and the impact towards the Indonesia-Malaysia relationship. History had demonstrated that both events were followed by some changes in the bilateral relationship. The 1965 coup for instance resulted the fall of Sukarno and the collapse of PKI, while reformasi brought the fall of Suharto and the collapse of New Order. However, it was undeniable that the demands of international situation especially during and after the Cold War were significant factor in driving of those events.
Keywords: Cold War; Indonesia-Malaysia relations; The 1965 coup; domestic politics; reformasi.