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The meta-ultramafic bodies of Gomati and Nea Roda, e. Chalkidiki, are part of the Serbomacedonian Massif, which is considered an extension of the Rhodope Massif which also includes meta-ultramafic and mafic occurrences. Podiform chromitites in the East Chalkidiki have undergone metamorphism and their host rocks are pervasively serpentinized. Chromitites are widely used as petrogenetic tools to unravel the settings under which they have formed and which have subsequently affected the mantle section. Likewise, various alternating/metasomatic processes can also be studied focusing on chromitites while focusing on their mineralogy and geochemistry. Under this scope, it is important to specify primary and secondary mineralogical and chemical features in order to answer to the following questions: a) under what settings have the East Chalkidiki chromitites were generated and b) under what settings and conditions have they been modified. The answer in those questions will offer insights in the general geotectonic evolution of the Serbomacedonian Massif. Electron microprobe (Eugen F. Stumpfl Laboratory of the Leoben University, Austria, using a Superpobe Jeol JXA 8200) and LA-ICP-MS analyses (system at the NAWI Graz Central Lab for Water, Minerals and Rocks) were conducted mainly upon spinel-group minerals. Focus was given in secondary mineral phases such as chlorite, diopside, garnet, platinum-group minerals (PGM) to further assist the interpretations. The mantle section of e. Chalkidiki hosts both Al-rich and Cr-rich chromitites. Using the normalized trace element patterns of the spinel-group minerals, the primary core was distinguished from the metamorphic rims. The main chemical differences include increase in Ti, Zn, Co, Mn during metamorphism, and those abundances point to a peak of amphibolite facies. In the pristine cores, the included PGM are primary, whereas desulphurized and zoned PGM are included in modified spinel. Garnet and chlorite were crystallized during greenschist facies, as their chemistry implies. Secondary diopside hosted in chromitite and diopsidite demonstrate subduction features (LA-ICP-MS) and this is in agreement with the serpentinite geochemistry (ICP-MS). The platinum-group element (PGE) abundances (Instrumental Neutron Activation Analysis) of chromitites have been preserved and increase in Pd/Ir ratios in some cases are attributed to fractionation, with the main mechanism for chromitite formation being the partial melting that the mantle source has underwent. The spinel grains of the Al-rich chromitites demonstrate flat normalized trace element profiles typical of back-arc chromitites, whereas chromite from the Cr-rich chromitites demonstrate patterns related with supra subduction zone (SSZ) settings. Similar environments have been described for the chromitite occurrences of the Rhodope Massif (Colás et al., 2014; González-Jiménez et al., 2015). After their formation the ultramafic section along with the chromitites were introduced into a subduction zoned reaching amphibolite facies that were later-on overprinted by greenschist facies. These events have also been recorded upon the meta-pellitic rocks of the Serbomacedonian Massif (Kydonakis et al., 2014; Siron et al., 2018). These results point to common settings being responsible for the formation and modification of both the chromitites of Serbomacedonian and the Rhodope Massifs. [ABSTRACT FROM AUTHOR]