<jats:title>Abstract</jats:title><jats:p>A cyclic tetrapeptide, designated massiliamide, was isolated from the liquid culture of the Gram-negative bacterium <jats:italic>Massilia albidiflava</jats:italic> DSM 17472<jats:sup>T</jats:sup>. The structure was elucidated through extensive spectroscopic analysis, including HR-MS and 1D and 2D NMR experiments. The absolute configuration was determined using the Marfey´s method. Massiliamide showed potent inhibitory activity towards tyrosinase with an IC<jats:sub>50</jats:sub> value of 1.15 µM and no cytotoxicity.