Abstract: Background and Objective: Cis-parinaric acid (CPA) is a naturally occurring polyunsaturated fatty acid found in the seeds of Makita tree. This chromophore is a C18 conjugated fatty acid fluoresces at 410 nm, when excited at 325 nm. Lipoxygenase (LOX) enzyme mediated reaction products are involved in inflammation. The objective of the work was to study the in vitro inhibition and interaction of soy LOX-1 with CPA. Methodology: Lipoxygenase-1 activity was performed by measuring the end products, hydroperoxy octadecadienoic acid using linoleic acid substrate in the presence or absence of CPA. The kinetics is deduced with varying concentration of substrate and inhibitor. The association constant for the binding of CPA to LOX-1 was determined by observing tryptophan quenching of the LOX-1 with the addition of CPA. Results: Cis-parinaric acid inhibits soy LOX-1 activity with an IC50 value of 18.8 μM. The mechanism of inhibition of soy LOX-1 by CPA is competitive with the Ki value of 9.8 μM. The binding constant for the binding of CPA to soy LOX-1 is 6.0±0.5×104 M–1. CPA binds close to the iron cofactor of LOX with the distance of CPA to the iron atom being 3.3 Å. Conclusion: Kinetic and docking studies demonstrated that CPA is a non-redox type of inhibitor, inhibiting LOX-1 by competitive manner.