Contrasting marriage patterns and resultant fertility differences are reported for Indonesia and the Philippines. The analysis was based on data from the Indonesian Intercensal Survey of 1976, the Philippine National Demographic Survey of 1973, and time series of census materials for both countries. The Javanese marry at a much earlier age, 1st marriages are normally arranged in Indonesia, marriage is more nearly universal among the Javanese, there is frequent noncontinuation or even nonconsummation of the 1st marriage, and there is very common and rapid remarriage. This pattern contrasts in every particular with the Philippine pattern. Age at marriage has increased in both countries recently, but the female mean age at marriage in Indonesia is still much lower than that in the Philippines, 19.6 and 22.9 respectively in 1970. Socioeconomic differentials in nuptiality patterns for both countries, especially the education and the residence variables, are examined. Neither population has practiced fertility control to a great extent until recently. Therefore, cumulative fertility is strongly related to the timing and duration of marriage. Some aggregate relationships between nuptiality and fertility are considered. Completed parity among early-marrying Filipino women was 8.3 as compared to a 4.8 parity for women marrying late. The comparable figures for the Java-Bali sample were 5.4 versus 4.2. The reason average parities were much higher among Filipino than among Java-Bali women is that, despite the earlier marrying age in Indonesia, there is a higher prevalence of marital dissolution. In the future, birth control may replace nuptiality as the main factor influencing fertility.