<p>Cadmium (Cd) contamination represents a significant environmental challenge, posing serious risks to human health. This study aims to examine the relationship between two trace metals (zinc (Zn) and cadmium (Cd)) in <i>Lactuca sativa</i>, a leafy vegetable known for its propensity to accumulate heavy metals. Two weeks after germination, lettuce seedlings were subjected to Cd treatments (0 and 10 µM), in combination with varying Zn concentrations (1, 10, and 100 µM). The efficacy of Zn supplementation in alleviating Cd toxicity was notably observed in the shoots, where partial to full recovery of key photosynthetic parameters, including transpiration rate, water use efficiency, maximum quantum efficiency (Fv/Fm), and maximum operating efficiency of PSII (Fv'/Fm'), was documented. Additionally, the efficiency of Zn supply in restricting Cd increase in aerial parts was obvious, particularly at the highest Zn concentration (100 µM), which coincided with increased Zn accumulation. By contrast, at this level, root Cd absorption was enhanced, accompanied by a marked inhibition of Zn uptake. These results indicate an antagonistic effect linking these two heavy metals, likely due to competitive interactions for shared membrane transporters. Overall, the findings suggest that appropriate Zn supplementation may serve as a viable agronomic strategy to mitigate Cd accumulation in species grown in lands contaminated with Cd, thereby offering a potential solution for improving food safety and environmental health.</p>