In this work, we investigated the photochemical degradation of the complex Fe(III)-EDDS which is increasingly used in studies of advanced oxidation processes. After irradiation of the aqueous solution, HPLC-HRMS analyses are used to identify the degradation products of EDDS. Six different products are separated and identified with specific chemical formulas. Proposed mechanisms based on the initial photo-redox process can explain the formation of all the products. They correspond to oxidized products with a shorter carbon chain and aldehyde and/or carboxylic acid functions. Among, them the formation of formaldehyde is also proposed in the mechanisms. This study is the first one that identifies degradation products of Fe(III)-EDDS complex and proposes a complete mechanism of degradation that can be applied for other iron complexes.