ABSTRACTThe question of standardizing the measurement of lipoprotein(a) [Lp(a)] has been discussed for many years, but the unavailability of automated methods insensitive to the structural heterogeneity of Lp(a) and the transition to a new unit of measurement have delayed this process. The aim of this study is to compare, in subjects undergoing regular lipoprotein apheresis (LA) treatment (31 subjects, mean age 62 ± 11 years, female 7/31), Lp(a) measurements performed using routine polyclonal antibodies with a method that recognizes a single copy of apo(a) per molecule. This pilot study for adopting an assay insensitive to apo(a) size polymorphism showed a good match with the traditional method: correlations between pre‐LA and post‐LA measures show an R2 of 0.89 and 0.76, respectively. Despite the interpretative problem caused by adopting different units of measurement, we believe that moving to an assay insensitive to the dimensional variation of apo(a) represents a necessary change to standardize, improve, and extend the accuracy and diagnostic power of Lp(a).