The main objective of this study was to determine the impact of allelopathic potentials of non-polluted (reference site) and polluted Psidium guajava leaf powder on germination and metabolites accumulation in Vicia faba. Psidium guajava leaves were collected from Edko (non-polluted) and Amrayya (polluted) regions to represent the two types of leaves respectively. The experimental design was a complete randomized with three replicates. Non-polluted and polluted P. guajava dry leaves powder was mixed with sandy loam soil in ratios to get different concentrations (1, 2, 3 and 4%) in addition to soil without powder as control. The dry weight (g seedling^-1) and shoot length (cm) of V. faba seedlings achieved their reductions at high concentration percentages (3 and 4%). On the other hand, P. guajava leaves in the polluted region exhibited more reduction in seedlings root length (cm) compared with the leaves of non-polluted. The decrease in pigment content of leaves as well as carbohydrate and protein content in seedlings shoot and root was remarkable due to polluted rather than non-polluted leaf powder. The concentration of different nutrient elements varied with respect to the element, organ and applied powder. The increased polymorphism and the genomic template stability (GTS) percentages may indicate the adaptation of V. faba plant to non-polluted treatments than to the polluted ones. The leaf cells from V. faba treated with 4% non-polluted and polluted powders showed marked differences in their metabolic processes that explain the noticeable differences in fine structure of leaf cells.