The highly atherogenic lipoprotein(a) (Lp(a)) is expressed at elevated concentrations in 20% of the population. However, accurate measurement of Lp(a) is challenging because Lp(a) size is heterogeneous in the population. Additionally, assays are not standardized to a single reporting unit (current available immunoassays measure in either mass concentration or molar units) and a once available universal reference material has been exhausted. While many international practice guidelines now support universal once-per lifetime testing in all adults, the lack of specific treatments to lower Lp(a) and reduce cardiovascular risk has resulted in a lack of Lp(a) measurements in most individuals. Clinical laboratorians should understand these challenges such that accurate measurement of Lp(a) can be achieved.