PIP: Morality in Peninsular Malaysia has reached a level that is quite similar to that prevailing in the low mortality countries. This article systematically documents changes in mortality levels and differentials in Malaysia over time and relates these to changes in development indicators and health-related policies. Remedial measures undertaken by the authorities including the expansion of hospital and health services into the estates, together with a comprehensive malaria-eradication program, improvements in sanitation laws, and increased provision of public utilities and education, resulted in beriberi being eliminated and the incidence of malaria, typhus, and smallpox being greatly reduced by the time of World War II. The gain in life expectancy over the period of 1957-1979 was greatest for the Malay, the most significant period being 1957-1967, which saw the introduction of rural health programs. The infant mortality rate and the neonatal and post-neonatal rates declined substantially for all ethnic groups in Peninsular Malaysia for the same time period. Although the lower infant mortality of the Chinese can be explained by their advantageous socioeconomic position the same reason cannot explain the lower decline in infant mortality levels of the Indians. Much still needs to be done to narrow, if not to eliminate, the existing mortality differentials of different groups in the country. Overall, the quality of life of the general population can be further enhanced by reducing the high mortality level of disadvantaged groups.