In the state of Hawaii, Samoan mothers are known for the large average birthweight and low percentage of low birthweight (< 2500 g) of their infants, in spite of the relatively low socio-economic status of the population. This paper reports the findings of a temporal trend analysis of birth outcomes of Samoan women and identifies worrying changes. Data were obtained from Hawaii birth certificates. Single live births to Hawaii-resident Samoan and Caucasian women from 1979 to 1994 were included in the study. Infants of Samoan women experienced a 75 g decline in mean birthweight and an increase in the percentage of low (< 2500 g) and very low (< 1500 g) birthweight from 2.6 and 0.4 to 3.8 and 0.8 respectively. During the same time, infants of Caucasian mothers experienced an increase in mean birthweight and a decline in low birthweight, while very low birthweight did not change. Maternal socio-demographic characteristics explained only part of the findings and use of prenatal care did not appear to be associated with any birth outcome indicators. Multiple regression analyses identified an adjusted loss of 50.8 g in birthweight and a 1.48 increase in the odds ratio of small-for-gestational-age associated with birth at the end (1991-4) compared with the beginning (1979-82) of the study period. Further studies focusing on maternal health status and psycho-social variables, including the effect of acculturation-related stress, are warranted to identify at least some of the determinants of the changes identified by this analysis.