Objectives: We investigated the relationship between premature rupture of the membranes (PROM) and early mortality among triplets in the United States. Study design: Analysis was conducted on matched and linked triplet sets born to mothers in the United States between 1995 and 1997. The generalized estimating equation framework was used to generate odds ratios after capturing the effects of sibling correlations within triplet clusters. Results: Triplets exposed to PROM were twice as likely to experience stillbirth (OR=2.17, 95% CI [1.26-3.41]), neonatal death (OR=2.23, 95% CI [1.70-3.0]) and infant death (OR=2.21, 95% CI [1.72-2.85]), as compared to those who did not. The population-attributable risk for early mortality due to PROM was 11-12%. Conclusions: Triplets associated with PROM had a significantly higher level of early mortality than those without. Assuming a causal relationship, 11-12% of all early deaths among triplets in the United States are accounted for by PROM. © 2003 Elsevier Ireland Ltd. All rights reserved.