The chemical characterization of ancient mortars allowed the researchers to answer relevant questions about production technologies, raw materials supply, construction phases and state of decay. In this work one hundred and sixteen samples were collected from different structures during two archaeological excavations carried out in Sagunto’s city centre (Valencia, Spain). The studied area has been interested by several continuous phases of occupation since the Iberian Epoch (5th century BC) to the present times [1,2]. The samples were analysed employing X-ray fluorescence and Inductively coupled plasma mass spectrometry to determine major and trace elements. The obtained data was statistically processed with Sagunto’s Castle mortar results [3], allowing us to identify the construction phases of most of the wall structures, confirming the particular effectiveness of Rare Earth Elements analysis to distinguish mortars from different periods. In conclusion, according to this data, the state of conservation of the different mortars has been evaluated. [1] Ripollés, Opulentissima Saguntum (2004) 165. [2] Monserrat, Arse 41 (2007) 231. [3] Gallello et al., Microchem. J. 132 (2017) 251