The new concept of thrombosis associated with an inflammatory process is called thromboinflammation. Indeed, both thrombosis and inflammation interplay one with the other in a feed forward manner amplifying the whole process. This pathological reaction in response to a wide variety of sterile or non-sterile stimuli eventually causes acute organ damage. In this context, neutrophils, mainly involved in eliminating pathogens as an early barrier to infection, form neutrophil extracellular traps (NETs) that are antimicrobial structures responsible of deleterious side effects such as thrombotic complications. Although NETosis mechanisms are being unraveled, there are still many regulatory elements that have to be discovered. miRNAs are important modulators of gene expression implicated in human pathophysiology almost two decades ago. Among the different miRNAs implicated in inflammation, miR-146a is of special interest because: (i) it regulates among others, TLR/NF-B axis which is of paramount importance in inflammatory processes, (ii) it regulates the formation of NETs by modifying their ageing phenotype, (iii) it has expression levels that may decrease among individuals up to 50%, controlled in part by the presence of several polymorphisms. In this manuscript, we will review the main characteristics of miR-146a biology. In addition, we will detail how miR-146a is implicated in the development of two paradigmatic diseases in which thrombosis and inflammation interact, cardiovascular diseases and sepsis, and their association with the presence of miR-146a polymorphisms and the use of miR-146a as a marker of cardiovascular diseases and sepsis.Thieme. All rights reserved.