The trade-off between controlling inflation and creating jobs is a typical issue that macroeconomic policy makers deal with and the Phillips Curve is a traditional way of explaining the relationship between the two. This paper will provide the comparative analysis of Japan and Malaysia between 2000 and 2020 to determine the dynamics of inflation and unemployment in two economies with structural and institutional differences. Japan is a developed economy which has had long-term deflation, slow growth and a fast-aging population, whereas Malaysia is a developing economy which has had moderate inflation and comparatively low unemployment assisted by a looser labour market and a demand-based growth. The study analyses descriptive statistical analysis on secondary data obtained through the World Bank through the World Development Indicators as well as a graphical interpretation of the Phillips Curve to determine the validity of the inflation-unemployment trade-off. The results indicate that Japan has a weak and flattened Phillips Curve that is constrained in part by structural reasons, deflationary anticipations and smothered wage expansion, which restrict the ability of demand-side approaches. Conversely, Malaysia has a stronger negative correlation between inflation and unemployment in a stable period, whereas this is not the case in major external shocks, like the 2008 oil price boom and the COVID-19 pandemic. The research paper finds that, although the Phillips Curve is clearly an effective tool of analysis, its own applicability is strongly context-specific and is inseparable with structural and institutional implications of macroeconomic policy formulation