Heavy metal contamination in aquatic ecosystems is an environmental concern due to the persistence and accumulation of metals in aquatic organisms. Water spinach (Ipomoea aquatica) has the ability to absorb and accumulate heavy metals from its growing environment, making it a potential bioindicator of aquatic pollution. This study aimed to analyze the concentrations of lead (Pb) and iron (Fe) in the leaves and stems of Ipomoea aquatica and determine differences in their concentrations among sampling stations in Lake Siombak, Medan Marelan. Samples were collected from three stations representing aquatic vegetation, residential, and fish-pond areas, with three replicates at each station. The samples were dried, digested using nitric acid, and analyzed using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Data were analyzed descriptively and statistically using the Kruskal-Wallis test. The results showed that Pb concentrations in leaves ranged from 0.573–2.295 mg/kg, while concentrations in stems ranged from 0.385–15.136 mg/kg. The highest Pb concentration was found in stems at Station I. Fe concentrations were generally higher in leaves, with the highest concentration of 138.77 mg/kg recorded at Station I. Statistical analysis showed that Pb and Fe concentrations did not differ significantly among sampling stations (p > 0.05). Pb concentrations in both leaves and stems exceeded the maximum reference value of 0.20 mg/kg based on BPOM Regulation No. 23 of 2017, whereas Fe concentrations remained below the comparison value of 425 mg/kg dry weight. These findings indicate that I. aquatica has the ability to accumulate Pb and Fe and has potential as a bioindicator of heavy-metal contamination in Lake Siombak. However, the high Pb accumulation indicates that the consumption of I. aquatica from the study area requires caution.