This article presents a review of 3 possible explanations for the seemingly apparent paradox of favorable birthweight outcomes among Mexican Americans. Evidence is grouped into 3 explanations: cultural, under-reporting, and bio-medical. With an emphasis on the link between acculturation among Mexican Americans and their perinatal outcomes, the key correlates associated with lower rates of low birth weight (LBW) are examined and critiqued. This review of the literature also explores policy and health implications for this important public health issue.