Abstract INTRODUCTION: A positive family history of premature coronary artery disease can prompt the assessment of children of the family for coronary risk factors like hypertension, obesity and dyslipidemia. This study was performed to determine the relationship between lipoprotein (a), apolipoprotein A1 and B100 in patients with a positive history of premature myocardial infarction and their offspring. methods: This cross-sectional study was conducted on 91 parents and their offspring (91 children). The parents were randomly selected from among patients with premature myocardial infarction hospitalized in the critical care unit of Vali-e-Asr hospital (Birjand, Iran). Lipoprotein (a), apolipoprotein A1 and B100 were measured in both groups. results: Our study showed a significant relationship between lipoprotein (a) levels in parents and their children. High lipoprotein (a) and high apolipoprotein B100 in parents and their children were also significantly related. CONCLUSIONS: We recommend that lipoprotein (a) and apolipoprotein B100 be measured in children with familial history of premature myocardial infarction. Keywords: Premature myocardial infarction, lipoprotein (a), risk factors, offspring, apolipoproteins.