Therefore, we hypothesized that certain <i>PCSK9</i> genetic variants may modify the association between LC n-3 PUFA intake and CVD risk.<b>Objective:</b> We determined whether a <i>PCSK9</i> variant (rs11206510), which has been identified for early onset myocardial infarction (MI), modified the association of LC n-3 PUFAs with nonfatal MI risk in Costa Rican Hispanics.<b>Design:</b> We analyzed cross-sectional data from 1932 case subjects with a first nonfatal MI and 2055 population-based control subjects who were living in Costa Rica to examine potential gene-environment interactions.