The non-native signal crayfish (Pacifastacus leniusculus) may alter ecosystems and affect local biota by changing the availability of chemical elements that accumulate and may act as contaminants. This elemental availability may change spatially. In this study, we investigate the differences in elemental exposure in signal crayfish in the Rabaçal River, Portugal, focusing on possible intrapopulation differences between individuals from the core and front (n=30 each) of an invasion gradient. We examined 57 elements, including essential (EEs): Mn, Co, Ni, Cu, Zn, Mg, Ca, Fe, Se, V, S; potentially toxic (PTEs): Cd, Hg, Pb, U, As, Sr, Ba, Cr, Zr, Cs, Tl; and technology-critical elements (TCEs): Ti, Rb, La, Ce, Pr, Gd, Dy, Ho, Er, Yb, Ga, Ge, Hf, Ta, In, Re, Te, Pt, and explored their relationship with signal crayfish diet, behaviour, and parasitic load. Significant differences in element concentrations were found between individuals from the core and front (mean µg/kg, dry weight). Individuals from the front showed higher levels of Co: (476 vs. 297), V: (390 vs. 262), Mn: (2.6 x 104 vs. 1.0 x 104), Hg: (2526 vs.1658), and Ta: (21 vs. 11). Conversely, individuals from the core had higher levels of Pb: (361 vs. 234), and Sr: (39772 vs. 20018). These differences likely reflect dietary and behavioural variations since front individuals have higher δ15N values and more exploratory behaviour, possibly relying more on higher trophic levels such as macroinvertebrates. In contrast, core individuals, with higher parasitic load, likely experienced reduced metabolic efficiency and their diet relied more on lower trophic levels such as plant detritus. This study increases our understanding of contaminant accumulation along an invasion gradient, offering insights for management practices to minimise ecological impacts to other trophic levels.