The state of Hawaii has had near-universal health insurance coverage f
or the last 20 years. Its highly diverse population offers the opportu
nity for a unique, natural experiment in the United States on the exam
ination of social differences in health care utilisation when financia
l barriers are removed. Therefore, the objective of this study is to e
xamine predictors of prenatal care utilisation patterns in the four ma
jor ethnic groups in Hawaii. The data used in this study are the 1979-
92 Hawaii livebirth vital record files. A total of 165301 singleton li
vebirths to Hawaii-resident mothers of Caucasian, native Hawaiian, Jap
anese or Filipino ancestry were selected. Despite near-universal healt
h care coverage in Hawaii, a surprising number of women did not adequa
tely utilise prenatal care, with large differences between groups. Mul
tivariate analyses indicated that similar maternal socio-demographic f
actors were associated with prenatal care use in each ethnic group. So
cial variation continues to exist among all ethnic groups even in the
presence of universal access to care. These data emphasise the need to
address the distinct cultural needs of populations for providing heal
th services, and further challenge the assumption that removal of fina
ncial barriers will ensure a high level of prenatal care use.