Abstract. Lipoxygenases (LO) have been implicated in asthma, immune disorders, and various cancers and as a consequence, there is great interest in isolating selective LO isozyme inhibitors.Currently, there is much use of baicalein as a selective human platelet 12-LO (12-hLO) inhibitor however, our current steady-state inhibition data indicates that baicalein is not selective against 12-hLO versus human reticulocyte 15-LO-1 (15-hLO-1) (15/12 = 1.3), in vitro. However, in the presence of detergents baicalein is slightly more selective (15/12 = 7), which may imply greater selectivity in a cell based assay but has yet to be proven. The mechanism of baicalein inhibition of 15-hLO is reductive, which computer docking suggests is through direct binding of the catecholic moiety of baicalein to the iron. A structurally related flavonoid, apigenin, is not reductive, however, computer docking suggests a hydrogen bond with Thr591, may account for its inhibitor potency.