This paper discusses existing estimates of the number of deaths due to the 1918 Spanish influenza pandemic in Indonesia, particularly in the core island of Java. Chandra (2013) estimated these deaths to be 4.26 to 4.37 million. The paper substantiates that these estimates are the result of a methodology that relies on an overestimated annual average population growth rate of 1.75% during 1880-1930. Using a more realistic growth rate of 1.1% per year reduces the estimate to a still considerable 1.47 million deaths in 1918. A rough estimate of excess mortality among the non-Indonesian population in Java and the whole population in the outer islands of Indonesia suggest a total of 2 million excess deaths related to the Spanish flu in 1918-19. The paper also briefly scrutinises the available vital statistics obtained from the village registers in Java. Correcting these as much as possible for under-recording confirms the impression that the estimates in Chandra (2013) are too high. The paper identifies opportunities for further historical demography research related to the 1918 flu pandemic in Indonesia.